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Basic Electrical Engineering, MCQs, U N I T 1-6, , Click on the Unit to Navigate, Unit 1, , Electromagnetism, , Unit 2, , Electrostatics and AC Fundamentals, , Unit 3, , Single Phase AC Circuits, , Unit 4, , Polyphase A.C. Circuits & Single phase, Transformers, , Unit 5, , DC Circuits, , Unit 6, , Work, Power, Energy and Batteries, , For Other Subjects Notes & MCQs

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Basic Electrical Engineering, , Multiple Choice Questions, UNIT I, ELECTROMAGNETISM, , 1. The complete path followed by the magnetic, flux is called, a. electric circuit, b. magnetic circuit, c. electromagnetism, d. electric field, ans: b, 2., Current carrying conductor is always, surrounded by, a. magnetic field, b. electric field, c. Electricity, d. current, ans: a, 3. The direction of magnetic field produced by, current carrying conductor is given by, a. Lenz’s law, b. right hand thumb rule, c. Fleming’s left hand rule, d. Kirchoff’s law, ans: b, 4. Imaginary lines of force originating from, magnet is called, a. current, b. resistance, c. flux, d. magnetic field, ans: c, 5. Region surrounded by magnet is called, a. magnetic field strength, b. magnetic field, c. electric field, d. resistance, ans: b, , 6. Lines of force is also called, a. flux, b. current, c. resistance, d. flux density, ans:a, 7. Lines of force passing per unit area is called, a. magnetic field, b. magnetic flux, c. magnetic flux density, d. magnetic field strength, ans:c, 8. unit of flux is, a. weber, b. wb/m2, c. Tesla, d. AT, ans:a, 9. Unit of flux density is, a. wb/m2, b. wb, c. AT/wb, d. A, ans:a, 10. Unit of magnetic field, a. wb/m2, b. wb, c. AT/wb, d. none of above, ans:b, 11. Unit of reluctance is, a. AT/wb, b. AT, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 1

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Basic Electrical Engineering, , Multiple Choice Questions, , c. Tesla, d. Wb/A, ans:a, , d. the ability of material to conduct magnetic, lines of force, ans: d, , 12. Opposition to the magnetic lines of force is, called, a. Flux, b. resistance, c. susceptance, d. reluctance, ans:d, , 17. An air gap is usually inserted in a magnetic, circuit, a. to prevent saturation, b. increase flux, c. decrease flux, d. increase mmf, ans: a, , 13. Unit of magnetic field strength is, a. AT/m, b. AT/wb, c.Tesla, d. ohms, ans: a, , 18. A magnetic circuit requires 800 ampere, turns to produce a certain amount of flux. If, exciting coil of 100 turns has 5 ohms resistance,, then the voltage to be applied to the exciting, coil must be, a. 40V, b. 20 V, c.10V, d. 5V, ans: a, , 14. The force on two current carrying, conductors in the same direction, a. have force of repulsion between them, b. have force of attraction between them, c. remains unaffected, d. none of above, ans: b, 15. Magneto motive force, proportional to, a. no. of turns of coil, b. current through the coil, c. both a and b, d. none of above, ans: c, , is, , directly, , 16. The term permeability for a material means, a. the no. of turns on an air core, b. the mmf required to produce one unit of, magnetic flux, c. the ability of a material to conduct electricity, through it, , 19. Permeability of a material is the ratio of, a. magnetic field to flux density, b. flux density to magnetic field strength, c. magnetic field strength to flux density, d. none of above, ans: b, 20. The term saturation related to magnetic, circuit means, a. magnetic field strength increases with, current, b. flux density increases with current, c. flux density remains constant if magnetic, field strength is increased, d. magnetic field strength remains constant if, flux density is increased., ans:c, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 2

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Basic Electrical Engineering, , Multiple Choice Questions, , 21. The lines of force produced by coil, completing their path through air, instead of, intended path is called, a. useful flux, b. saturated flux, c. air flux, d. leakage flux, ans: d, , b. does not vary with increasing the cross, sectional area, c. decreases with increasing cross sectional area, of material, d. decreases with increasing the length of, material, ans: c, 27. The correct relation stated as following is, , 22. The bulging of lines of force in air gap in a, magnetic circuit is called, a. leaking flux, b. merging, c. fringing, d. scattering, ans: c, 23. Relative permeability of vacuum is, a. 4π × 10-7 H/m, b. 1 H/m, c.1, d. ¼ H/m, ans: c, 24.MMF in magnetic circuit is analogous to, a. electric current in electric circuit, b. current density in conductor, c. electromotive force, d. resistance in electric circuit, ans:c, 25. Reluctance is analogous to, a. emf in electric circuit, b. resistivity, c. conductivity, d. resistance in electric circuit, ans: d, 26. The magnetic reluctance of a material, a. increases with increasing cross sectional area, of material, , 𝑁, , a. ф =𝑙/𝑎µ0µ𝑟, b. NI = B× l/a µ0µr, c. N=H×l, d. NI = ф × l/µ0µr a, ans: d, 28. The permeance in a magnetic circuit, corresponds to, a. resistance in an electric circuit, b. emf in an electric circuit, c. conductivity in electric circuit, d. conductance in an electric circuit, ans: d, 29. The ampere turns are, a. the product of the number of turns and, current of the coil, b. the number of turns of a coil through which, current is flowing, c. the currents of all turns of the coil, d. the turns of transformer winding, ans:a, 30. What will be the current flowing through, the ring shaped air core when number of turns, is 800 and ampere turns are 3200, a. 0.25, b.2.5, c.4.0, d. 0.4, ans:c, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 3

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Basic Electrical Engineering, , Multiple Choice Questions, , 31. Leakage factor is defined as the ratio of, a. flux in air gap by total flux, b. Total flux by useful flux, c. airgp flux by useful flux, d. total flux by flux produced by solenoid, ans: b, 32. Effect of fringing in magnetic circuit is, a. it increases flux density, b. its effective area of air gap decreases, c. it decreases flux density, d. none of above, ans:c, 33.The force experienced by unit north pole, when placed at point in a magnetic field is, called, a. magnetic field strength at that point, b. exerted force at that point, c.flux, d. magnetic field, ans:a, 34. The mechanical force acting on current, carrying on conductor when placed in magnetic, field is given by relation, a. F= N dф/dt, b. F= Blv sinӨ, c. F= BIL sinӨ, d. F=L di/dt, ans: c, 35. Which of the following has the highest, magnetic permeability?, a. paramagnetic substances, b. diamagnetic substances, c. ferromagnetic substances, d. vacuum, ans: c, 36. The perfect insulator for magnetic lines of, force is, , a. copper, b. rubber, c. glass, d. none of these, ans: d, 37. The force between two parallel current, carrying conductors is given by relation, a. I1I2 ×2× 10-7× l/d, b. I1 dl /I2 ×4π× 10-7, c. I1I2 /2π× 10-7, d. I12×4× 10-7ld, ans: a, 39. The magnitude of force experienced by, current carrying conductor placed in magnetic, field depends on, a. value of flux, b. magnitude of current flowing through, conductor, c. direction of current, d. all of above, ans: d, 40.Two current carrying conductor lying parallel, and close to each other. They are carrying, current in the opposite direction. The force, between them is, a. repulsive, b. Attractive, c. Zero, d. none of these, ans: a, 41. Two current carrying conductor lying, parallel and close to each other. They are, carrying current in the same direction. The, force between them is, a. repulsive, b. Attractive, c. Zero, d. none of these, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 4

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Basic Electrical Engineering, , Multiple Choice Questions, , ans: b, 42. Two current carrying conductor lying, parallel and close to each other are exerting, force of attraction on each other. The currents, are, a. very high, b. in opposite direction, c. low, d. in the same direction, ans: d, 43. Two current carrying conductor lying, parallel and close to each other are exerting, force of repulsion on each other. The currents, are, a. very high2, b. in opposite direction, c. low, d. in the same direction, ans: b, 44. Two conductors are carrying 1000A and, 5000A currents respectively are 5cm apart. The, force per meter length between two conductors, is, a. 100 N/m, b. 40 N/m, c.30 N/m, d. 20 N/m, ans: d, 45. Magnetic field strength due to N long, straight current carrying conductors in the same, direction is given by, a. H= NI/ 4πd, b. H= I/ 2πd, c. H= NI/ 2πd, d. H=NI/l, ans: c, 46. A conductor of 10cm length carrying a, current of 5A placed in uniform magnetic field, , of flux density 1.25T at 300 to the lines of flux., Force acting on conductor will be, a.0.3125N, b. 3.125N, c.1.325N, d. 5.321N, ans: a, 47.Fleming’s left hand rule is used to find, a. Magnitude of induced emf in conductor, b. Direction of magnetic field in conductor, c. Direction of force on current carrying, conductor, d. Magnitude of flux density, ans: c, 48. Which statement is correct related to, magnetic field produced due to current carrying, conductor, a. direction of rotation of screw to advance in, the direction of current gives the direction of, magnetic field, b. If right hand curled fingers shows the, direction of current, thumb gives the direction, of magnetic field, c. if direction of rotation of screw shows current, ,tip gives the direction of magnetic field, d. all of these, ans: a, 49. Force experienced by current carrying, conductor when placed in magnetic field will be, zero when, a. current in the conductor is maximum, b. Angle between conductor and field is zero, c. Both a &b, d. None of these, ans: b, 50. Relative permeability is defined as the ratio, of, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 5

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Basic Electrical Engineering, , Multiple Choice Questions, , a. magnetic field strength in a medium to flux, density in the same medium, b. Magnetic flux density in vacuum to magnetic, field strength in vacuum, c. Magnetic flux density in other medium to flux, density in vacuum, d. Magnetic flux density in vacuum to flux, density in other medium, ans: c, 51. The ability with which the magnetic material, allows the flux to pass through a given medium, is called, a. susceptibility, b. permeability, c. conductivity, d. reluctivity, ans: b, 52. Unit of permeability is, a. A/m, b. H/m, c. I/m, d. m/H, ans: b, 53. Permeability of free space or vacuum is, defined as the ratio of, a. magnetic flux density in vacuum to magnetic, field strength, b. Magnetic flux density in other medium to, magnetic field strength, c. Magnetic field strength to magnetic flux, density in vacuum, d. Magnetic field strength in medium to flux, density in other medium, ans: a, 54. Right hand thumb rule is used to find out, a. direction of induced emf, b. direction of magnetic field due to current, carrying conductor, , c. magnitude of force experienced, d. direction of force, ans: a, 55. In left hand rule, thumb always represents, a. current, b. voltage, c. magnetic field, d. direction of force on conductor, ans: d, 56. The force between two long current, carrying conductor is inversely proportional to, a. current in one conductor, b. product of current in two conductors, c. distance between the two conductors., d. radius of conductors, ans: c, 57. While comparing magnetic and electric, circuit, the point of dissimilarity exists while, considering, a.mmf and emf, b. Reluctance and resistance, c. flux and current, d. permeance and conductance, ans: c, 59. Permeance is to reluctance as conductance, is to, a. inductance, b. resistance, c. capacitance, d. ampere turns, ans: b, 60. A straight cylindrical solenoid has a flux of, 12mwb and a flux density of 0.9T. The diameter, of solenoid must be, a.130cm, b. 13cm, c.10cm, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 6

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Basic Electrical Engineering, , Multiple Choice Questions, , d.5cm, ans : b, , 65. the mmf of ring is_____, a.5000AT, b. 7200AT, c.750AT, d. 7500AT, ans:d, , 61. 1 tesla is given as, a. 1wb/m2, b. 1wb/cm2, c.1mwb/cm2, d. 1wb/mm2, ans: a, 62. Which part of the magnetic path requires, largest mmf, a.coil, b.core, c.airgap, d. inductance, ans: c, 63. Soft steel and iron alloy allow easy passage, of a magnetic flux because, a. of its high elasticity, b. of its high permeability, c. of its high conductivity, d. of its high reluctance, ans: b, 64. Magnitude of the magnetic field produced, by a coil is proportional to, a. Permeability of the core material, b. the no. of turns of coil, c. the magnitude of current flow through the, coil, d. the product of all above, ans:d, Following data should be used for solving 65 to, 67, A coil is wound uniformly with 300 turns over, steel ring of relative permeability 900, having, mean circumference of 40mm and cross, sectional area of 50mm2. A current of 25A is, passed through coil, , 66. The reluctance of ring is______, a.7×107 AT/Wb, b. 0.7×106 AT/Wb, c.6×107 AT/Wb, d. 6×105 AT/Wb, ans: b, 67.The value of flux is _________, a.10.7 Wb, b.70 mWb, c.10.7mWb, d. 107 mwb, ans: c, 68. The relative, is__________, a. 1, b. less than 1, c. greater than 1, d. 1000, ans: a, , permeability, , of, , air, , 69. Relative permeability of all non magnetic, materials is_____, a. 300, b. 0.7, c.1, d. 0, ans: c, 70. Which of the following is non magnetic, material?, a. iron, b. Mild steel, c. brass, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 7

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Basic Electrical Engineering, , Multiple Choice Questions, , d. Silicon steel, ans: c, 71. Which of the following is magnetic material?, a. copper, b. silicon steel, c. aluminium, d. brass, ans: b, , 76. A strength of an electromagnet is, determined by, a. reluctance, b. permeability of the core, c.mmf, d. all of above, ans: d, 77. The strength of the magnetic field around a, conductor is directly proportional to, a. voltage across the conductor, b. current in the conductor, c. type of material of conductor, d. none of above, ans: b, , 72. Flux in the air gap is called, a. leakage flux, b. total flux, c. useful flux, d. all of above, ans: c, 73. A magnetic circuit has a mmf of 400AT and a, reluctance of 2 × 105 AT/wb. The magnetic flux, in the magnetic circuit is, a. 3 × 10-5Wb, b.2 × 10-3Wb, c.1.5 × 10-2Wb, d. 2.5 × 10-4Wb, ans: b, 74. A 2cm long coil has 10 turns and carries a, current of 750mA. The magnetizing force of the, coil is, a. 225 AT/m, b. 675 AT/m, c.450 AT/m, d. 375 AT/m, ans: d, 75. The reluctance of a magnetic circuit varies, with, a. length × area, b. length / area, c. area/length, d. (length)2 + area, ans: b, , 78. Reluctance of magnetic material is, a. less than non magnetic material, b. more than non magnetic material, c. equal to that of non magnetic material, d. none of above, ans: a, 79. The denser the flux, a. stronger is the magnetic field, b. weaker is the magnetic flux, c. no effect on the strength of field, d. none of above, ans: a, 80. The direction of induced e.m.f. is given by, a. Flemings right hand rule, b. Flemings left hand rule, c. faradays law of electromagnetic induction, d. crock screw rule., ans:a, 81. Magnitude of induced e.m.f. in a generator, depend on, a. flux density, b. magnitude of current, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 8

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Basic Electrical Engineering, , Multiple Choice Questions, , c. rate of cutting flux, d. Rate of current discharge., ans:c, , d. The induced current is the same in all, positions, ans:b, , 82. According to Lenz’s law direction of induced, e.m.f. is., a. Same as cause produced, b. Perpendicular to cause produced, c. opposite to cause produced, d. Non above, ans:c, , 86. In which of the following situations a, voltage is induced in a conductor?, a. The conductor moves through the air., b. The conductor is connected to a battery., c. The conductor is connected to a motor., d. The conductor is moved in a magnetic field., ans:d, , 83. According to Faraday’s Laws of, electromagnetic induction, an e.m.f.is induced, in a conductor whenever it, a. Lies in magnetic field, b. Cuts magnetic flux, c. moves parallel to the direction of the, magnetic field, d. lies perpendicular to the magnetic flux., ans:b, , 89. In case of dynamically induced emf,, direction of induced emf is given by, a. Fleming’s right hand rule, b. Lenz’s law, c. Faraday’s first law, d. Faraday’s second law, ans:a, , 84. When a magnet moves past an object, it will, produce eddy currents in the object if the, object is, a. a solid, b. an insulator, c. a conductor, d. made from the magnetic material, ans:d, 85. Electricity can be generated by rotating a, wire loop between the poles of a magnet. In, which of the following positions would induce, the greatest current in the loop?, a. The plane of the loop is parallel to the, magnetic field., b. The plane of the loop is perpendicular to the, magnetic field., c. The plane of the loop makes an angle of 45°, with the magnetic field., , 90. Emf induced in a coil due to its own current, is called __________Induction., a. Mutual, b.Self, c. Dynamic, d. Static, ans:b, 91. Emf induced in a coil due to current change, in neighboring coil is called_________, induction., a. Mutual, b. Self, c. Dynamic, d. Static, ans:a, 92. Co-efficient of self induction is also called, as__________, a. self- induction, b. Inductance, c. Self- inductance, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 9

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Basic Electrical Engineering, , Multiple Choice Questions, , d. Induction, ans:a, , c. Henry, d. Linkages, ans:c, , 93. The property of a coil due to which it, opposes the change of current flowing through, itself is called_____, of the coil., a. Static inductance, b. Dynamic inductance, c.Self inductance, d. Mutual inductance, ans:c, , 98. Unit of induced emf is_________, a. Volt, b. Ampere, c. Henry, d. Linkages, ans:a, , 94. ____________is used to sense the flow of, current in a electric circuit., a. Ammeter, b. Voltmeter, c. Wattmeter, d. Galvanometer, ans:a, , 99. The property of one coil due to which it, opposes the change in the other coil is, called…………., between two coils., a. Dynamic inductance, b. Static inductance, c. Self inductance, d. Mutual inductance, ans:d, , 95. The phenomenon of the self induction is felt, only when the current in the coil is, a. Changing, b. Increasing, c. Decreasing, d. All the above, ans:a, , 100. The unit, is_________, a. Volt, b. Ampere/ Volt, c. Henry, d. Linkages, ans:c, , 96. The negative sign in the induced emf of self, induction indicates that energy is being, absorbed from the electric circuit and stored as, _______ energy in the coil., a. mechanical, b. Electronic, c. electric, d. Magnetic, ans:d, , 101. In the expression 𝑒 =, , 97. Unit of co-efficient of self induction of the, circuit is______, a. Volt, b. Ampere, , of, , mutual, , 𝑀𝑑𝑖1, 𝑑𝑡, , inductance, , , M represents, , a. Mutual induction, b. Mutual inductance, c. Number of lines of force, d. None of these, ans:b, 102. If 0.75 V is induced emf and resistance, offered by the coil is 200 ohm then induced, current is, a. 3.75 A, b. 3. 75 mA, c. 3.75μA, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 10

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Basic Electrical Engineering, , Multiple Choice Questions, , d. 37.5 mA, ans:b, 103. If magnetic flux changes from 0.8 Wb to, 0.3 Wb, then change in flux is______ Wb., a. 1.1, b. 0.5, c. -0.5, d. -1.1, ans:c, 104. If Number of turns of coil is 200 and if the, current is 100mA, then MMF is ________, a. 2000 AT, b. 200 AT, c. 20 AT, d. 0.5 AT, ans:c, 105. Leakage factor is also called as, a. Fringing, b. Coefficient of inductance, c. Magnetic coefficient, d. Hopkinson’s coefficient, ans:d, 106. Movement of electrons are called as, a. MMF, b. Current, c. Voltage, d. Flux, ans:b, 107. Flux density is equal to ________ of flux, and area of cross – section., a. Sum, b. Difference, c. Product, d. Fraction, ans:d, 108. NI expression is called, , a. MMF, b. EMF, c. Flux linkage, d. Magnetic intensity, ans:a, 109. Expression NI/L is called, a. MMF, b. EMF, c. Flux linkage, d. Magnetic field strength, ans:d, 110. Expression for mutual inductance is, a. –L dI/dt, b. MdI / dt, c. N2 Ф2/ I1, d. NФ/I, ans:c, 111. Faraday’s law of electromagnetic induction, is e=, a. –NdФ/dt, b. MdI / dt, c. N2 Ф2 / I1, d. NФ/I, ans:a, 112. The constant K in case of mutual induction, is equal to, a.Ф1/Ф2, b.Ф2/Ф1, c.Ф1/I1, d.Ф2/I1, ans:d, 113. Product of the permeability μoμr is equal to, a. Magnetic flux, b. Magnetic field, c. Magnetic intensity, d. Magnetic flux density / magnetic field, strength, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 11

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Basic Electrical Engineering, , Multiple Choice Questions, , ans:d, 114. Expression for self induced emf is, a. –L dI/dt, b. MdI1 / dt, c. N2 Ф2/ I1, d. NФ/I, ans:d, 115. __________is normally termed as flux, linkages., a. Ф, b. dФ/dt, c. NФ, d.Ф/I, ans:c, 116. The term NФ/I is generally called as______, a. Self inductance, b. Mutual inductance, c. Flux linkage, d. Induced emf, ans:a, 117. In the expression for reluctance S = l/μA of, a conduced, letter A represents_________ of, the conductor., a. Total area, b. Surface area, c. Cross- sectional area, d. None of these., ans:c, 118. When a current carrying conductor is, brought in to magnetic field, the force that, moves the conductor depends on, a. direction of current., b. length of conductor, c. value of current, d.all of the above, ans:d, , 119. Two current carrying conductors lying, parallel to each other are exerting a force of, attraction on each other. The currents are, a. Very high, b. in opposite direction, c. low, d. in the same direction, ans:d, 120. Two conductors are lying parallel and close, to each other. They are carrying currents in, opposite directions. The force between them is., a. Repulsive, b. attractive, c. zero, d. none of these, ans:a, 121. When a coil consisting of single turn, rotates at uniform speed in magnetic field, the, induced emf is____, a. steady, b. alternating, c. changing, d. reversing, ans:b, 122. The emf induced in a conductor of length 1, meter moving at a right angles to a uniform, magnetic field of flux density 1.5 wb/m2 with, velocity of 50 m/s is., a. 0, b.1.5 v, c. 75 v, d. 100 v, ans:c, 123. Which of following statements is incorrect., a. Whenever flux linking with the coil or circuit, changes, an emf is induced., b. The direction of dynamically induced emf can, be determined by Fleming’s right-hand rule., , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 12

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Basic Electrical Engineering, , Multiple Choice Questions, , c. the coefficient of self-inductance is, proportional to the square of number of turns, on it., d. Coefficient of coupling for tightly coupled coil, is zero., , ans: d, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 13

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Basic Electrical Engineering, , Multiple Choice Questions, , Unit II, Part (a) ELECTROSTATICS, 1. A dielectric material must be________, a. resistor, b. Insulator, c. Conductor, d. Semiconductor, ans:b, , c. smaller than the capacitance of smallest, capacitor, d. average of the capacitance of all capacitor, ans:c, , 2. The energy stored in capacitance is given, by__________________________, a. C2V, b. CV2/2, c. C2V/2, d. CV, ans:b, 3. Electrolytic capacitors can, for__________________________, a. a.c. only, b. d.c. only, c. both a.c. and d.c., d. 50 Hz a.c., ans:b, , be, , used, , 4. If two 10 µF capacitors are connected in, parallel, then the effective capacitance will, be_________, a.2.5 µF, b.40 µF, c.0.4 µF, d.20 µF, ans:d, 5. If a number of capacitors are connected in, series then the total capacitance of combination, is_____, a. greater than the capacitance of largest, capacitor, b. greater than the capacitance of any capacitor, , 6.The total capacitance of five capacitor each of, 10 µF in series is________________, a.10 µF, b.2 µF, c.25 µF, d. none of these, ans:b, 7. Two capacitors of capacitance C1=0.1 µF and, C2=0.2 µF are connected in series across 300V, source. The voltages across C1 will be________, a. 100 V, b. 200 V, c. 150 V, d. 300 V, ans:b, 8. A capacitor stores 0.4C charge at 2 V. Its, capacitance is___________________________, a. 0.4 F, b. 0.2 F, c. 3.2 F, d. 0.8 F, ans:b, 9. A20mF capacitor is in series with a 150 ohm, resistor. The combination is placed across a 40V, dc source. Time constant of the circuit, is_____________________, a. 8 s, b. 3 s, c. 6 s, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 1

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Basic Electrical Engineering, , Multiple Choice Questions, , d. 2.4s, ans: b, , ans: a, , 10. Three capacitors of values 3 µF, 6 µF, and 12, µF are connected in parallel across an a.c., source. The maximum current pass through, ________________, a.3 µF, b.6 µF, c.12 µF, d. all the capacitors, ans:c, 11.As per Coulomb’s law___________________, a. F= Q1Q2 / εoεrd2, b. F= Q1Q2 / 4𝜋d2, c. F= Q1Q2 / 4𝜋 εoεrd2, d. F= Q1Q2 /4𝜋 εoεrd, ans: c, 12. Electric field intensity at any point in an, electric field is equal to_______, a. potential gradient, b. (potential gradient)2, c. (potential gradient)1/2, d. (potential gradient)1/3, ans: a, 13. The lines of forces due to isolated charged, particle are___________, a. always straight, b. always curved, c. sometimes curved, d. none of the above, ans: a, 14. The direction of electric field due to positive, charge is___, a. away from the charge, b. towards the charge, c. both (a) and (b), d. none of the above, , 15. The unit of capacitance is, a. Volts/Coulomb, b. Coulomb/Volt, c. Ohms, d. Henry/Wb, ans: b, 16. There is repulsive force between two, charged objects when, a. Charges of unlike sign, b. they have the same number of protons, c. charges are of same sign, d. they have the same number of protons, ans: c, 17. The capacitance of a capacitor is not, affected by, a. distance between plates, b. area of plates, c. thickness of plates, d. all of the above, ans: c, 18. When there is an equal amount of positive, and negative charges on an object the object is, a. Positively charged, b. negatively charged, c. neutral, d. supercharged, ans:c, 19. Which of the following statements is, correct?, a. Air capacitors have a black band to indicate, the outside foil, b. Electrolytic capacitor must be connected in, the correct polarity, c. Ceramic capacitors must be connected in the, correct polarity, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 2

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Basic Electrical Engineering, , Multiple Choice Questions, , d. Mica capacitors are available in capacitance, value of 1 to 10 µF, ans: b, 20. Three capacitors each of the capacity C are, given. The resultant capacity 2/3 C can be, obtained by using them, a. all in series, b. all in parallel, c. two in parallel and third in series with this, combination, d. two in series and third in parallel across this, combination., ans:c, 21. For which of the following parameter, variation, the capacitance of the capacitor, remains unaffected?, a. Distance between plates, b. Area of the plates, c. Nature of dielectric, d. Thickness of the plates, ans: d, 22. Which of the following expression is correct, for electric field strength?, a. E = D/𝝐, b. E = D2/𝝐, c. E = 𝝅D, d. E = 𝝅D2, ans: a, 23. Which of the following statement is true?, a. The current in the discharging capacitor, grows linearly, b. The current in the discharging capacitor, grows exponentially, c. The current in the discharging capacitor, decays exponentially, d. The current in the discharging capacitor, decreases constantly, ans:c, , 24. In a capacitor the electric charge is, deposited on, a. metal plates, b. dielectric, c. both (a) and (b), d. none of the above, ans:a, 25. Which of the following materials has the, highest value of dielectric constant?, a. Glass, b. Vaccum, c. Ceramics, d. Oil, ans: c, 26. Capacitance of air capacitor increases with, a. increase in plate area and decrease in, distance between the plates, b. increase in plate area and distance between, the plates, c. decrease in plate area and value of applied, voltage, d. reduction in plate area and distance between, the plates, ans: a, 27. A capacitor consists of, a. two insulators separated by a conductor, b. two conductor separated by a dielectric, c. two insulators only, d. two conductors only, ans:b, 28. A paper capacitor is usually available in the, form of, a. tubes, b. rolled foil, c. disc, d. meshed plates, ans:b, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 3

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Basic Electrical Engineering, , Multiple Choice Questions, , 29. Air capacitors are generally available in the, range, a. 10 to 400 pF, b. 1 to 20 pF, c. 100 to 900 pF, d. 20 to 100 pF, ans:a, 30. The unit of capacitance is, a. Henry, b. Ohm, c. Farad, d. Farad/m, ans:c, , 34. Energy stored in the electrical field of a, capacitor C when charged from a D.C, source of, voltage V is equal to …….. Joule, a. ½ CV2, b. ½ C2V, c. CV2, d. C2V, ans:a, 35. The absolute permittivity of free space is, given by, a. 8.854 x 10-9 F/m, b. 8.854 x 10-10 F/m, c. 8.854 x 10-11 F/m, d. 8.854 x 10-12 F/m, ans:d, , 31. A capacitor charged to 200V has 2000 µC of, charge. The value of capacitance will be, a. 10 F, b. 10 µF, c. 100 µF, d. 1000 µF, ans:b, , 36. The relative permittivity of free space is, given by, a. 1, b. 10, c. 100, d. 1000, ans:a, , 32. Voltage across capacitor at any time‘t’, during charging from a D.C. source of voltage V, is given by, a. ν = Ve-t/λ, b. ν = V(1-e-t/λ), c. ν = V2e-t/λ, d. ν = V2(1-e-t/λ), ans:b, , 37. When 4 Volt e.m.f. is applied across a 1, Farad capacitor, it will store energy of, a. 2 Joule, b. 4 Joule, c. 6 Joule, d. 8 Joule, ans:d, , 33. The ratio of electric flux density to electric, field intensity is called ………. of the medium, a. permeability, b. permittivity, c. reluctance, d. capacitance, ans:b, , 38. The capacitor preferred for high frequency, circuits is, a. air capacitor, b. mica capacitor, c. electrolytic capacitor, d. paper capacitor, ans:b, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 4

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Basic Electrical Engineering, , Multiple Choice Questions, , 39. If a 6µF capacitor is charged to 200 V the, charge in Coulomb will be_______________, a. 800 µC, b. 900 µC, c. 1200 µC, d. 1600 µC, ans:c, 40. Which of the following capacitors is marked, for polarity____________________?, a. air, b. paper, c. mica, d. electrolyte, ans: d, 41. Which of the following capacitor are usually, used for radio frequency tuning__________, a. air, b. paper, c. mica, d. electrolyte, ans: b, 42. The time constant of an R-C circuit is, defined as the time during which capacitor, charging voltage actually rises to ---------------percent of its ---------- value, a.37, initial, b.63.2, initial, c.63.2, final, d.37, final, ans: c, 43. The time constant of an R-C circuit is, defined as the time during which capacitor, charging current actually falls to ---------------percent of its initial maximum value, a.37, b.63, c.42, d.73, , ans: a, 44. Permittivity is expressed in_______, a. Farad/sq-m, b. weber/metre, c. Farad/meter, d. weber/ square metre, ans:c, 45. Dielectric strength of a material depends, on_________________, a. moisture content, b. temperature, c. thickness, d. all of the above, ans: d, 46. 1 Volt /metre is same as, a. 1 metre/coulomb, b. 1 Newton metre, c. 1 Newton /Coulomb, d. 1 Joule /Coulomb, ans: c, 47. The relative permittivity of air is__________, a.0, b.1.0006, c. 8.854 × 10−12, d. none of the above, ans:b, 48. The relative permittivity of a material is 10., Its absolute permittivity will be, a. 8.854 × 10−11 𝐹/𝑀, b. 9 × 108 𝐹/𝑀, c. 5 × 10−5 𝐹/𝑀, d. 9 × 105 𝐹/𝑀, ans: a, 49. The capacitance of a capacitor is ………, relative permittivity, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 5

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Basic Electrical Engineering, , Multiple Choice Questions, , a. directly proportional to, b. inversely proportional to, c. independent of, d. directly proportional to square of, ans: a, 50. An air capacitor has the same dimensions, that of a mica capacitor. If the capacitance of, mica capacitor is 6 times that of air capacitor,, then relative permittivity of mica is, a. 36, b. 12, c. 3, d. 6, ans: d, 51. The most convenient way of achieving large, capacitance is by using, a. multiplate construction, b. decreased distance between plates, c. air as dielectric, d. dielectric of low permittivity, ans: a, 52. Two capacitors of capacitance C1 and C2 are, connected in parallel. A charge Q given to them, is shared. The ratio of charges Q1/Q2 is, a. C2/ C1, b. C1/ C2, c. C1 C2, d. 1/ C1 C2, ans: b, 53. Two capacitors have capacitance 25 µF, when in parallel and 6 µF when in series. Their, individual capacitances are, a. 12 µF and 13 µF, b. 15 µF and 10 µF, c. 10 µF and 8 µF, d. none of the above, ans:b, , 54. If the dielectric of a capacitor is replaced by, a conducting material the, a. capacitor will get heated up owing to eddy, currents, b. plates will get short-circuited, c. capacitor can store infinite charge, d. capacitance will become very high, ans:b, 55. The total capacitance of two condensers is, .03µF when joined in series and 0.16µF when, connected in parallel. The products of two, capacitance will be__________, a.5.33, b.2, c.3, d.0.48, ans:d, 56. Joule / Coulomb is the unit of, a. Electric field potential, b. Potential, c. charge, d. none of the above., ans:b, 57 .A 10µF capacitor in series with an 1 M Ohm, resistor is connected across a100 V d. c. supply., Determine the time constant of the circuit, a. 10 sec., b. 0.1 sec, c. 10mSec, d. 100 Sec, ans:a, 58. A 10µF capacitor in series with an 1 M Ohm, resistor is connected across a100 V d. c. supply., Determine the initial value of charging current., a. 1mA, b. 0.1 mA, c. 0.01mA, d. 1.00A, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 6

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Basic Electrical Engineering, , Multiple Choice Questions, , ans:b, 59. A 10µF capacitor in series with an 1 M Ohm, resistor is connected across a100 V d. c. supply., Determine the initial rate of rise of voltage, across the capacitor., a. 0.1V/s, b. 10V/s, c. 0.01V/s, d. 1V/s, ans:b, , 63. A fully charged capacitor of 10µF has a, potential difference of 100V across its, terminals. It is discharged through 1 K Ohm, resistor. Find discharging current at 2m Sec., a. - 0.0818A, b. - 0.01A, c. - 0.00818A, d. - 1A, ans:a, , 60. A 10µF capacitor in series with an 1 M Ohm, resistor is connected across a100 V d. c. supply., Determine the capacitor voltage after a time, equal to the time constant., a.36V, b.36.6V, c.63.2V, d.63 V, ans:c, , 64. A fully charged capacitor of 10µF has a, potential difference of 100V across its, terminals. It is discharged through 1 K Ohm, resistor. Find initial rate of fall in voltage across, capacitor., a. 10 4 V/s, b. -10 4 V/s, c. -1 4 V/s, d. 10A, ans:b, , 61. A 10µF capacitor in series with an 1 M Ohm, resistor is connected across a100 V d. c. supply., Determine the voltage across the capacitor, 3sec. after switch on., a.25.92V, b.259.2V, c.2.592V, d.25V, ans:a, , 65. A fully charged capacitor of 10µF has a, potential difference of 100V across its, terminals. It is discharged through 1 K Ohm, resistor. Find time constant of the circuit., a. 0.1sec, b. 1sec, c. 0.01sec, d. 0.001sec, ans:c, , 62. A fully charged capacitor of 10µF has a, potential difference of 100V across its, terminals. It is discharged through 1 KΩ resistor., Find Initial discharging current., a.1A, b.10A, c.0.01A, d.0.1A, ans:d, , 66. A capacitor consists of two similar plates, each 10cm x 10cm mounted parallel and, opposite to each other. What is the value of, capacitance when distance between them is, 1cm and dielectric used is air., a. 8.854 pF, b. 8.854 µF, c. 8.854 mF, d. 8.854 F, ans: a, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 7

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Basic Electrical Engineering, , Multiple Choice Questions, , 67. The capacitance of capacitor formed by two, parallel plates each 200 cm2 in area separated, by dielectric of 4mm thick is 0.0004µF. If, voltage of 20000 V is applied then the total, charge on the plate is, a. 8µC, b. 8mC, c. 8nC, d. 8pC, ans: a, 68. A parallel plate capacitor has plate area of, 2m2 spaced by three slabs of dielectric, materials. The relative permittivity’s are 2,3 and, 6 respectively and thickness are 0.4mm, 0.6mm, and 0.12 mm respectively. Find the combined, capacitance., a. 0.000295 x 10-6 F, b. 0.00295 x 10-6 F, c. 0.0295 x 10-6 F, d. 0. 295 x 10-6 F, ans: b, 69. What is the unit of charge?, a. Volt-Amp, b. Henery, c. Farad, d. Coulomb, ans: d, 70. What will be the capacitance of four, capacitors of equal capacitance ‘C’ when, connected in parallel, a. 4C, b. C/4, c. 3C/4, d. C, ans: a, , a. magnetic field, b. electric field, c. magnetic field and electric field, d. neither magnetic field nor electric field, ans: b, 72. One Farad is the same as, a. One Coulomb/Volt, b. One Joule/Coulomb, c. One Joule/Volt, d. One Coulomb /Joule, ans: a, 73 . If Q be the charge and C be the capacitance, then the energy stored in the capacitor is, a. 1/2QC, b. 1/QC, c. Q2/2C, d. Q/2C, ans: c, 74.What capacitance must be placed in series, with a 15µF capacitor to give a total capacitance, of 5µF, a. 4µF, b. 7.5µF, c. 10µF, d. 25µF, ans: b, 75. One Coulomb charge equals the charge on, a. 6.42 x 10 18 electrons, b. 6.24 x 10 18 atoms, c 6.24 x 10 12electrons, d. none of these, ans: a, 76. The capacitance of parallel plate capacitor is, given as, a. C = Є0 A / d, b. C =, , Є0 d / A, , 71. A region around a stationary electric charge, has, Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 8

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Basic Electrical Engineering, , Multiple Choice Questions, , or A, d, d. C = Єr A / d, ans: c, c. C =, , 77. Two capacitors of 2 µF and 4 µF are, connected in parallel across 100 V D.C. supply., Determine (i) Energy stored on each capacitor, a. 0. 1 J and 0. 2 J, b. 0.01 J and 0.02 J, c 1 J and 2 J, d. 0.001 J and 0.002 J, ans: b, 78. The capacitance composit capacitor is given, as, oA, a. C = d, d2 d3, 1, +, +, r r r, 1, , 2, , 3, , b. C =, , Є0 d / A, or A, c. C =, d, d. C = Єr A / d, ans: a, , 80. The plate area of a parallel-plate capacitor is, 0.01 sq. m. The distance between the plates is, 2.5 cm. What would be its capacitance, if the, space between the plates is filled with an, insulating material of relative permittivity 5?, a 177.1 x 10-12 F, b. 1.771 x 10-12 F, c . 17.71 x 10-10 F, d. 17.71 x 10-12 F, ans: d, 81.A parallel-plate capacitor has two plates, each of area 2.5 m2 separated by three, dielectric materials of thickness 1, 2 and 3 mm, and relative permittivity’s of 2, 4 and 8, respectively. Calculate (i) the capacitance of the, capacitor, a. 1.60 x 10-8 F, b. 1.60 x 10-10 F, c. 1.60 x 10-12 F, d. 1.60 x 10-9 F, ans: a, , 79. The plate area of a parallel-plate capacitor is, 0.01 sq. m. The distance between the plates is, 2.5 cm. The insulating medium is air. Find its, capacitance., a 3.54 x 10-12 F, b. 35.4 x 10-12 F, c 3.54 x 10-10 F, d. 3.54 x 10-11 F, ans: a, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 9

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Basic Electrical Engineering, , Multiple Choice Questions, , Unit II, Part (b) AC FUNDAMENTALS, 1. A standard sinusoidal voltage wave changes, its polarity at________, a. maximum value, b. minimum value, c. zero value, d. none of the above, ans:c, 2. The period of a certain sine wave is 10, milliseconds. Its frequency is________, a.10 MHz, b.10 KHz, c.10 Hz, d.100 Hz, ans:d, 3. Two sine waves are said to be in phase with, each other if they achieve their______, a. zero value at the same time, b. maximum value at the time, c. minimum value at the same time, d. all of the above, ans:d, 4. The distance occupied by one complete cycle, of the wave is called its________, a. time period, b. wavelength, c. velocity, d. frequency, ans:a, 5. The rms value of a sine wave of peak value Im, is given by_______, a. Im/√2, b. Im, c. Im/2, d. Im/π, , ans:a, 6.The average value of a sine wave of maximum, value Im over one cycle is_______, a. Im/π, b. 2Im/π, c. zero, d. Im/2, ans:c, 7. The rms value of a sine wave of maximum, value 10A equals a dc current of, ______ampere., a.7.07, b.6.37, c.5, d.5.77, ans:a, 8.The rms value of a sinusoidal voltage with, peak-to-peak value of 240 V is________V., a.84.84, b.77.82, c.94.68, d.89.15, ans:a, 9. The time period of a sinusoidal waveform, with 200 Hz frequency is________second., a.0.05, b.0.005, c.0.0005, d.0.5, ans:b, 10. The peak value of a sine wave is 400 V. Its, average value is_________, a.254.6 V, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 10

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Basic Electrical Engineering, , Multiple Choice Questions, , b.282.6 V, c.400 V, d.565.5 V, ans:a, , a. 150 V, b. 216.5 V, c. 125 V, d.108.25 V, ans:b, , 11. The form factor of a sine wave is_____, a.1.01, b.1.11, c.1.21, d. none of the above, ans:b, 12. A current is said to be alternating when it, changes in_______, a. magnitude only, b. direction only, c. both magnitude and direction, d. neither magnitude nor direction, ans:c, 13. An alternating current of 50 Hz frequency, and 100 A maximum value is given by______, a.𝑖 = 200 𝑠𝑖𝑛628𝑡, b.𝑖 = 100 𝑠𝑖𝑛314𝑡, c.𝑖 = 100√2 𝑠𝑖𝑛314𝑡, d.𝑖 = 100√2 𝑠𝑖𝑛157𝑡, ans:b, 14. An alternating current of 50 Hz frequency, has a maximum value of 100 A. Its value 1/600, second after the instant current is zero will, be________, a. 25 A, b. 12.5 A, c. 50 A, d. 75 A, ans:c, 15.A sinusoidal voltage varies from zero to a, maximum of 250 V. The voltage at the instant of, 60° of the cycle will be________, , 16. An alternating current is given by the, expression 𝑖 = 200 sin(314𝑡 +, , 𝜋, 3, , ) amperes., , The maximum value and frequency of the, current are_________, a. 200 A, 50 Hz, b. 100√2, 50 Hz, c. 200 A, 100 Hz, d. 200 A, 25 Hz, ans:a, 17.The average value of the current 𝑖 =, 𝜋, 2, , 200 sin 𝑡 from 𝑡 = 0 to 𝑡 = is ______, a. 400 π, 400, 𝜋, 1, c.400, 𝜋, d.400, , b., , ans:b, 18. When two quantities are in quadrature, the, phase angles between them will be________, a.45°, b.90°, c.135°, d.60°, ans:b, 19.The alternating voltage 𝑒 = 200 sin 314𝑡 is, applied to a device which offers an ohmic, resistance of 20 Ω to the flow of current in one, direction while entirely preventing the flow in, the opposite direction. The average value of the, current will be_________, a.5 A, b.3.18 A, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 11

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Basic Electrical Engineering, , Multiple Choice Questions, , c.1.57 A, d.1.10 A, ans:b, 20. The ac system is preferred to dc system, because_______, a. ac voltages can be easily changed in, magnitude, b. dc motors do not have fine speed control, c. high voltage ac transmission is less efficient, d. dc voltage can not be used for domestic, appliances, ans:a, , a. 0.02 second, b. 0.01 second, c. 0.04 second, d. 0.05 second, ans:c, 25. A sine wave has a maximum value of 20 V., Its value at 135° is______, a. 10 V, b. 14.14 V, c. 15 V, d. 5 V, ans:b, , 21.In ac system, we generate sine waveform, because_______, a. it can be easily drawn, b. it produces least disturbance in electrical, circuits, c. it is nature’s standard, d. other waves can not be produced easily, ans:b, , 26. An alternating voltage is given by 𝑣 =, 30 𝑠𝑖𝑛314𝑡 .The time taken by the voltage to, reach 30 V for the first time is_____, a. 0.02 second, b. 0.1 second, c. 0.03 second, d. 0.005 second, ans:d, , 22.__________will work only on dc supply., a. electric lamp, b. refrigerator, c. electroplating, d. heater, ans:c, , 27. A sinusoidal current has a magnitude of 3 A, at 120°. Its maximum value will be_____, a.√3 A, , 23.An alternating voltage is given by 𝑣 =, 20 sin 157𝑡. The frequency of the alternating, voltage is_____, a.50 Hz, b.25 Hz, c.100 Hz, d.75 Hz, ans:b, 24. An alternating current is given by 𝑖 =, 10 sin 314𝑡. The time taken to generate two, cycles of current is____, , √3, , b. 2 A, c.2√3 A, d. 6 A, ans:c, 28. An alternating current is given by 𝑖 =, 10 𝑠𝑖𝑛314𝑡. Measuring time from 𝑡 = 0, the, time taken by the current to reach +10 V for the, second time is_________, a. 0.05 second, b. 0.1 second, c. 0.025 second, d. 0.02 second, ans:c, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 12

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Basic Electrical Engineering, , Multiple Choice Questions, , 29. An alternating voltage is given by 𝑣 =, 100 𝑠𝑖𝑛314𝑡 volts. Its average value will, be________, a. 70.7 V, b. 50 V, c. 63.7 V, d. 100 V, ans:c, 30. An alternating current whose average value, is 1 A will produce_________1 A dc under, similar conditions., a. less heat than, b. more heat than, c. the same heat as, d. none of the above, ans:b, 31. A sinusoidal alternating current has a, maximum value of Im. Its average value will, be_______, 𝐼𝑚, 𝜋, 𝐼𝑚, b. 2𝜋, 𝐼𝑚, c. 2 𝜋, , a., , d.none of the above, ans:c, 32. The area of a sinusoidal wave over a halfcycle is________, a.𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 2, b.2 × 𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒, c.𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 𝜋, d. .𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 2𝜋, ans:b, 33. An alternating voltage is given by 𝑣 =, 200 𝑠𝑖𝑛314𝑡. Its rms value will be_____, a. 100 V, b. 282.8 V, c. 141.4 V, d. 121.4 V, , ans:c, 34. A sinusoidal voltage is represented as 𝑣 =, 𝜋, , 141.4 sin(314.18𝑡 − 2 ) . Its rms value of, voltage, frequency and phase angle are, respectively_______, a. 141.42 V, 314.16 Hz, 90°, b. 100 V, 100 Hz, -90°, c. 87.92 V, 56 Hz, 90°, d. 100 V,50 Hz, -90°, ans:d, 35. When two sinusoidal waves are 90° out of, phase, then__________, a. both have their peak values at the same, instant, b. both have their minimum values at the same, instant, c. one has its peak value; while the other has, zero value, d. none of these, ans:c, 36. The direction of current in an ac circuit, is___________, a. always in one direction, b. varying from time to time, c. unpredictable, d. from positive to negative, ans:b, 37. Consider the sinusoidal waves: 𝐴 sin(𝜔𝑡 +, 30°) and 𝐵 sin(𝜔𝑡 − 60°) . The phase angle, relationship between the two waves________, a. B-wave lags A-wave by 90°, b. B-wave lags A-wave by 60°, c. B-wave lags A-wave by 30°, d. B-wave and A-wave are in phase, ans:a, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 13

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Basic Electrical Engineering, , Multiple Choice Questions, , 38. A sinusoidal voltage is expressed as 𝑣 =, 20 sin(314.16𝑡 +, , 𝜋, ), 3, , V. Its frequency and, , phase angle respectively are____________, a. 314.16 Hz, 60°, b. 60Hz, 60°, c. 50 Hz, 60°, d. 50 Hz, -60°, ans:c, 39. A sinusoidal voltage v1 leads another, sinusoidal voltage v2 by 180°. Then__________, a. voltage v2 leads voltage v1 by 180°, b. both voltage have their zero values at the, same time, c. both voltages have their peak values at the, same time, d. all of the above, ans:d, , d. none of the above, ans:c, 43. The rms value of sinusoidally varying current, is_________that of its average value., a. more than, b. less than, c. same as, d. none of the above, ans:a, 44. Alternating voltages and currents are, expressed in rms values because______, a. they can be easily determined, b. calculations become very simple, c. they give comparison with dc, d. none of the above, ans:c, , 40.The rms value of an ac sinusoidal current is, 10 A. Its peak value is_________, a. 7.07 A, b. 14.14 A, c. 10 A, d. 28.28 A, ans:b, , 45.The average value of sin2θ over a complete, cycle is_________, a. +1, b. -1, , 41. If A=10∠45° and B=5∠15°, then the value of, A/B will be_________, a. 50∠60°, b. 2∠60°, c. 2∠-30°, d. 2∠30°, ans:d, , 46.The average value of sinθ over a complete, cycle is_________, a. zero, b. +1, c. -1, , 42. When a phasor is multiplied by –j, it gets, rotated through in the counterclockwise, direction., a.90°, b.180°, c.270°, , 1, , c. 2, d. zero, ans:c, , d., , 1, 2, , ans:a, 47. An alternating current is given by 𝑖 =, 𝐼𝑚 𝑠𝑖𝑛𝜃. The average value of squared wave of, this current over a complete cycle is________, a. I2m/2, b. Im/π, c. 2Im/π, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 14

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Basic Electrical Engineering, , Multiple Choice Questions, , d. 2Im, ans:a, 48. The form factor of a sinusoidal wave, is______, a.1.414, b.1.11, c.2, d.1.5, ans:b, 49. The filament of a vacuum tube requires 0.4A, dc to heat it. The rms value of ac required, is______, a.0.4 × √2 A, b.0.4 ÷ 2 A, c.0.8 ÷ √2 A, d. 0.4 A, ans:d, 50. A100 V peak ac is as effective as_____dc., a. 100 V, b. 50 V, c. 70.7 V, d. none of the above, ans:c, 51. The form factor of a ________wave is 1., a. sinusoidal, b. square, c. triangular, d. sawtooth, ans:b, 52. Out of the following _________wave is the, peakiest., a. sinusoidal, b. square, c. rectangualr, d. triangular, ans:d, , 53. The peak factor of a sine waveform, is_______, a.1.11, b.1.414, c.2, d.1.5, ans:b, 54.When a 15V square wave is connected, across a 50V ac voltmeter, it will read______, a.15V, b.15 × √2 V, c.15/√2 V, d.none of the above, ans:a, 55.A sine wave has a frequency of 50 Hz. Its, angular frequency is_______radian/second., a.100π, b.50π, c.25π, d.5π, ans:a, 56. The period of a wave is____________, a. the same as frequency, b. time required to complete one cycle, c. expressed in amperes, d. none of the above, ans:b, 57. The form factor is the ratio of _________, a. peak value to rms value, b. rms value to average value, c. average value to rms value, d. none of the above, ans:b, 58. The period of a sine wave is 1/50 seconds., Its frequency is_______, a. 20 Hz, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 15

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Basic Electrical Engineering, , Multiple Choice Questions, , b. 30 Hz, c. 40 Hz, d. 50 HZ, ans:d, , a. mean value, b. rms value, c. peak value, d. average value, ans:b, , 59. An ac current is given by 𝑖 = 200 𝑠𝑖𝑛100𝜋𝑡., It will achieve a value of 100A, after_____second., 1, , a.900, 1, 800, 1, c., 700, 1, d.600, , b., , ans:d, 60. A heater is rated as 230V, 10KW, AC. The, value of 230V refers to___________, a. average voltage, b. rms voltage, c. peak voltage, d. none of the above, ans:b, 61. The peak value of a sine wave is 200V. Its, average value is_______, a.127.4V, b.141.4V, c.282.8V, d.200V, ans:a, 62. The rms value of a sine wave is 100A. Its, peak value is _______, a.70.7A, b.141.4A, c.150A, d.282.8A, ans:b, 63. The voltage of domestic supply is 220V. This, figure represents________, , 64. The rms value and mean value is the same, in the case of_______, a. traingular wave, b. sine wave, c. square wave, d. half wave rectified sine wave, ans:c, 65. For the same peak value which of the, following wave will have the highest rms value?, a.square wave, b.half wave rectified sine wave, c.triangular wave, d.sine wave, ans:a, 66. For the same peak value which of the, following wave will have the least mean value?, a. half wave rectified sine wave, b. triangular wave, c. sine wave, d. square wave, ans:a, 67. For a sine wave with peak value Imax, the rms, value is_______, a. 0.5Imax, b. 0.707Imax, c. 0.9Imax, d. 1.414Imax, ans:b, 68. Form factor is the ratio of_________, a. average value/rms value, b. average value/peak value, c. rms value/average value, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 16

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Basic Electrical Engineering, , Multiple Choice Questions, , d. rms value/peak value, ans:c, , d.346V, ans:d, , 68. For a sine wave with peak value Emax, the, average value is______, a. 0.636 Emax, b. 0.707Emax, c. 0.434 Emax, d. 1.414Emax, ans:a, , 73. A sine wave of voltage varies from zero to, maximum of 200V. How much is the voltage at, the instant of 30° of the cycle?, a.50V, b.82.8V, c.100V, d.173.2V, ans:c, , 69. The current in a circuit is given by: 𝑖 =, 100 sin 314𝑡 amperes. The maximum value and, frequency of current are_________, a.50√2 A, 100 Hz, b.100√2 A, 100 Hz, c. 100 A, 50 Hz, d. 70.7 A, 50 Hz, ans:c, 70. For a frequency of 200 Hz, the time period, will be_________, a. 0.05 S, b. 0.005 S, c. 0.0005 S, d. 0.5 S, ans:b, 71. An ac voltage of 50 Hz has a maximum value, of 50 V. Its value after 1/600 second after the, instant the current is zero will be_________, a.5V, b.12.5V, c.25V, d.43.8V, ans:c, 72. For 200V rms value triangular wave, the, peak voltage will be______, a.200V, b.222V, c.282V, , 74. How much rms current does a 300W, 200V, bulb take from the 200V, 50 Hz power line?, a.0.5 A, b.1.5 A, c.2 A, d. 3 A, ans:b, 75. The rms value of a half-wave rectified, current is 100 A. Its value for full-wave, rectification would be_________amperes., a.141.4, b.200, c. 200/π, d. 40/π, ans:a, 76. The rms value of a sinusoidal ac current is, equal to its value at an angle of ______degrees., a.90, b.60, c.45, d.30, ans:c, 77. The rms value of alternating current is given, by steady (dc) current which when flowing, through a given circuit for a given time, produces________, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 17

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Basic Electrical Engineering, , Multiple Choice Questions, , a. the more heat than produced by ac when, flowing through the same circuit, b. the same heat as produced by ac when, flowing through the same circuit, c. the less heat than produced by ac flowing, through the same circuit, d. none of the above, ans:b, 78. The square waveform of current has, following relation between rms value and, average value:, a. rms value is equal to average value, b. rms value of current is greater than average, value, c. rms value of current is less than average, value, d. none of the above, ans:a, 79. If a sinusoidal wave has frequency of 50 Hz, with 30A rms current, which of the following, equation represents the wave?, a.42.42 sin 314𝑡, b.60 𝑠𝑖𝑛25𝑡, c.30 sin 50𝑡, d.84.84 𝑠𝑖𝑛25𝑡, ans:a, 80. Which of the following waves has the, highest value of peak factor?, a. square wave, b. sine wave, c. half wave rectified sine wave, d. triangular wave, ans:c, 81.The frequency of domestic power supply in, India is_____, a. 200 Hz, b. 100 Hz, c. 60 Hz, , d. 50 Hz, ans:d, 82. The rms value of half wave rectified sine, wave is 200V. The rms value of full wave, rectified ac will be__________, a.282.8V, b.141.4V, c.111V, d. 100V, ans:a, 83. The voltage in a circuit follows the law: 𝑣 =, 100 𝑠𝑖𝑛𝜔𝑡. If the frequency is 25 Hz, how long, will, it take for the voltage to rise to 50V?, 1, , a.50 S, 1, S, 100, 1, c. S, 300, 1, d. S, 600, , b., , ans:c, 84. The negative maximum of a cosine wave, occurs at________, a.30°, b.45°, c.90°, d.180°, ans:d, 85. The rms value of pure cosine function, is_________, a. 0.5 of peak value, b. 0.707 of peak value, c. same as peak value, d. zero, ans:b, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 18

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Basic Electrical Engineering, , Multiple Choice Questions, , 86. An alternating voltage is given in volts by, expression 𝑣 = 326 𝑠𝑖𝑛314𝑡. Its rms value and, frequency are____, a.230V,50 Hz, b. 230V,100 Hz, c. 326V,50 Hz, d. 326V,100 Hz, ans:a, 87. According to which of the alternating, current values in the cross sectional area of a, conductor with regard to the heating effect is, selected?, a. peak value, b. half peak value, c. average value, d. rms value, ans:d, 88. The frequency of an alternating current, is________, a. the speed with which the alternator runs, b. the number of cycles generated in one, minute, c. the number of waves passing through a point, in one second, d. the number of electrons passing through a, point in one second, ans:c, 89. The equation of 50 Hz current sine wave, having rms value of 60 A is______, a.60 sin 25𝑡, b.60 sin 50𝑡, c.84.84 𝑠𝑖𝑛314𝑡, d42.42 𝑠𝑖𝑛314𝑡., ans:c, 90. An electric iron designed for 110 V AC, supply was rated at 500 W. It was put across a, 220 V supply. Assuming that at 110 V, it, , supplied 500 W output (i.e. no losses) at the, new voltage it will supply_________, a. 2500 W, b. 2000 W, c. 500 W, d. 250 W, ans:b, 91. The direction of current in an ac, circuit________, a. is from positive to negative, b. is always in one direction, c. varies from instant to instant, d. can not be determined, ans:c, 92. The angular frequency of an alternating, quantity is a mathematical quantity obtained by, multiplying the frequency “f” of the alternating, quantity by a factor_________, 𝜋, 2, , a., , b.π, c.2π, d.4π, ans:c, 93. The average value of an unsymmetrical, alternating quantity is calculated over, the_________, a. whole cycle, b. half cycle, c. unsymmetrical part of the waveform, d. first two cycles, ans:a, 94. The mean value of the current 𝑖 = 20 𝑠𝑖𝑛𝜃, 𝜋, , from θ=0 to θ=2 is_______, a.40π, 40, , b. 𝜋, , 1, 40, , c., , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 19

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Basic Electrical Engineering, , Multiple Choice Questions, , 𝜋, , d.40, ans:b, 95. A constant current of 2.8A exists in a, resistor. The rms value of current is______, a. 2.8 A, b. about 2 A, c. 1.4 A, d. undefined, ans:a, 96. An alternating current is represented as 𝑖 =, 𝜋, , 70.7 sin(520𝑡 + 6 ) . The frequency and rms, value of the current are_________, a. 82.76 Hz, 50 A, b. 41.38 Hz, 25 A, c. 41.38 Hz, 50 A, d. 82.76 Hz, 25 A, ans:a, 97. The time period or periodic time T of an, alternating quantity is the time taken in seconds, to complete_____________, a. one cycle, b. alternation, c. none of the above, d. Half cycle, ans: a, 98. The time period of an alternating quantity is, 0.02 second. Its frequency will be________, a. 25 Hz, b. 50 Hz, c. 100 Hz, d. 0.02 Hz, ans: b, 99. An ac current is given as i = 10 + 10 sin 314 t,, the average and rms values of the current, are____, a. 16.36 A, 17.07 A, , b. 10 A, 17.07 A, c. 10 A, 12.25 A, d. 16.36 A, 12.2 A, ans:c, 100. The size (cross-sectional area) of a, conductor, with regard to the heating effect, is, determined on the basis of ……….. value of, current to be carried by it, a. average value, b. peak value, c. rms value, d. peak to peak value, ans:c, 101. The form factor for dc supply voltage is, always, a. zero, b. unity, c. infinity, d. any value between 0 and 1, ans:b, 102. The ________ varying alternating quantity, can be represented as phasor., a) circular, b) sinusoidally, c) rectangular, d) triagular, ans:b, 103. The phasors are assumed to be rotated in, _________ direction., a) clockwise, b) anticlockwise, c) circular, d) all above, ans:b, 104. In practice, alternating quantities are, represented by their _______ values, a. rms, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 20

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Basic Electrical Engineering, , Multiple Choice Questions, , b. average, c. rectangular, d. polar, ans:a, 105. Alternating quantities of ____ frequencies, can be represented on same phasor diagram., a. Same, b. Different, c. multiple, d. all above, ans: a, 106. The phase of alternating quantity at any, particular instant is the fraction of ______, a. phase, b. time, c. time period, d. all above, ans:c, 107., , In the above figure, the phase quantity at A is, _______, a. T, b. T/2, c. T/3, d. T/4, ans:d, 108., , In the above figure, the phase quantity at B is, _______, a. T, b.T/2, c.3T/4, d. T/4, ans:c, 109. When phase of an alternating quantity is, positive it means that quantity has some, _______ instantaneous value at t=0, a. zero, b. positive, c. negative, d. none of the above, ans:b, 110. When phase of an alternating quantity is, negative it means that quantity has some, _______ instantaneous value at t=0, a. zero, b. positive, c. negative, d. none of the above, ans:c, 111. The difference between the _____ of two, alternating quantities is called the phase, difference., a. time, b. phase angle, c. Lengths, d. both a and b, ans:b, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 21

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Basic Electrical Engineering, , Multiple Choice Questions, , 112. The difference between the phase of two, alternating quantities is called the________., a. phase difference, b. sine difference, c. length difference, d. none of the above, ans:a, , 117. If v = Vm Sin ωt and i = Im Sin (ωt-Φ), the, ‘v’ is said to _______ ‘i’ by angle Φ, a. in phase, b. lagging, c. leading, d. all above, ans:c, , 113. When phase difference between the two, alternating quantities is zero, the two quantities, are said to be in _____, a. tandom, b. length, c. phase, d. time, ans:c, , 118. If v = Vm Sin ωt and i = Im Sin (ωt+Φ), the, ‘i’ is said to _______ ‘v’ by angle Φ, a. in phase, b. lagging, c. leading, d. all above, ans:c, , 114. When ____________ between the two, alternating quantities is zero, the two quantities, are said to be in phase., a. time difference, b. length difference, c. phase difference, d. none of the above, ans:c, 115. When phase difference between the two, alternating quantities is _______, the two, quantities are said to be in phase., a. one, b. unity, c. zero, d. π/2, ans:c, 116. If v = Vm Sin ωt and i = Im Sin (ωt-Φ), the ‘i’, is said to be _______ ‘v’ by angle Φ, a. in phase, b. lagging, c. leading, d. all above, ans:b, , 119. If v = Vm Sin ωt and i = Im Sin (ωt+Φ), the, ‘v’ is said to _______ ‘i’ by angle Φ, a. in phase, b. lag, c. lead, d. all above, ans:b, 120. If v = Vm Sin ωt and i = Im Sin ωt, the ‘i’ is, said to _______ ‘v’ by angle Φ, a. in phase, b. lag, c. lead, d. all above, ans:a, 121. With respect to reference, plus sign of, angle indicates _______, a. leading, b. lagging, c. in phase, d. none of the above, ans:a, 122. With respect to reference, minus sign of, angle indicates _______, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 22

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Basic Electrical Engineering, , Multiple Choice Questions, , a. leading, b. lagging, c. in phase, d. none of the above, ans:b, 123. With respect to reference, _____ sign of, angle indicates lead., a. division, b. plus, c. minus, d.dot, ans:b, 124. With respect to reference, _____ sign of, angle indicates lag., a. division, b. plus, c. minus, d.dot, ans:c, 125. The diagram in which different sinusoidal, alternating quantities of the same frequency,, are represented by individual phasors indicating, exact phase relationship is called ________, a. graph, b. still diagram, c. phasor diagram, d. picture, ans:c, 126. The diagram in which different sinusoidal, alternating quantities of the same _____, are, represented by individual phasors indicating, exact phase relationship is called phasor, diagram., a. time, b. frequency, c. sign, d. shape, ans:b, , 127. The lagging and leading word is relative to, the ______, a. base, b. range, c. reference, d. angle, ans:c, 128. Polar form of v = 100 sin(100πt+π/6) Volt is, ________, a.61.2371+j35.3553, b.70.7106∟30, c. 61.2371∟35.3553, d. 70.710+ j30, ans:b, 129. Rectangular form of V= 100 sin(100πt+π/6), Volt is ________, a.61.2371+j35.3553, b.70.7106∟30, c. 61.2371∟35.3553, d. 70.710+ j30, ans:a, 130. RMS value of current I = 25 + j40 Amp is, _______, a.57.99, b.47.1699, c.60, d.30, ans:b, 131. Two currents I1 = 1050 and I2 = 5 -100 A, flow in single phase AC circuit. Then I1+I2 =, ________, a. 5.5596+ j4.924 A, b. 5.55964.924 A, c. 7.296+ j12.58 A, d. None of the above, ans:a, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 23

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Basic Electrical Engineering, , Multiple Choice Questions, , 132. Two currents I1 = 1050 and I2 = 5 -100 A, flow in single phase AC circuit. Then I1-I2, =________, a. 5.5596+ j4.924 A, b. 5.5596∟4.924 A, c. 7.296+ j12.58 A, d. None of the above, ans:c, 133. Two currents I1 = 1050 and I2 = 5 -100 A, flow in single phase AC circuit. Then I1/I2, =________, a. 5.5596+ j4.924 A, b. 2150 A, c. 7.296+ j12.58 A, d. None of the above, ans:b, 134. The square of a j operator _____, a. can never be negative, b. can never be positive, c. could be either positive or negative, d. is equal to j, ans:b, 135. A complex number_____, a. is the same as imaginary number, b. has real and imaginary part, c. is negative number, d. is merely a technical term, ans:b, 136. The sum of (3+j6) and (-3-j6) is ____, a.0+j0, b.6+j12, c. -6-j12, d. 0-j12, ans:a, , b. 24-j14, c. -38-j34, d. -24-j14, ans:c, 138. A sinusoidal voltage is represented as: v =, 141.4 sin(314.18t-π/2). Its rms value of voltage,, frequency and phase angle are respectively____, a.141.42V, 314.16 Hz, 90 degrees, b. 100V, 50 Hz, -90 degrees, c. 87.92V, 56 Hz, 90 degrees, d. 200V, 50 Hz, -90 degrees, ans:b, 139. When two sinusoidal waves are 90 degrees, out of phase, then ____, a. both have their peak values at the same time, b. both have their minimum values at the same, time, c. one has its peak value, other has zero value, d. none of these, ans:c, 140. The direction of current in an AC circuit is, _____, a. always in one direction, b. varying time to time periodically, c. unpredictable, d. from positive to negative, ans:b, 141. Consider the sinusoidal waves: A sin, (ωt+30) and B cos(ωt-60). The phase angle, relationship between two waves is:, a. B wave lags A wave by 90 degrees, b. B wave lags A wave by 60 degrees, c. B wave lags A wave by 30 degrees, d. B wave and A wave are in phase, ans:d, , 137. The product of (-4-j7) and (6-j2) is______, a. -24+j14, Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 24

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Basic Electrical Engineering, , Multiple Choice Questions, , 142.When a phasor is multiplied by j and –j, it is, rotated through ______ degrees in the, anticlockwise direction respectively., a.90, 270, b.90, 90, c.90, 180, d.270, 90, ans:a, 143. If e1 = 100 sin2πf and e2 = 100 sin(2πf-Φ),, then _____, a. e1 lags e2 by Φ, b. e1 leads e2 by Φ, c. e2 lags e1 by Φ, d. none of the above, ans:c, 144.The phase difference between two, waveforms can be compared when they _____, a. have the same frequency, b. have the same peak value, c. have the same effective value, d. are sinusoidal, ans:a, 145. If two sinusoids of the same frequency but, of different amplitude and phase difference are, added, the resultant is a ______, a. sinusoid of same frequency, b. sinusoid of double the original frequency, c. sinusoid of half the original frequency, d. non-sinusoid, ans:a, 146. If the phasor is multiplied by j, then ____, a. only its magnitude changes, b. only its direction changes, c. both magnitude and direction change, d. none of the above, ans:b, , 147. In the complex number 4+j7, 7 is called the, ______ component, a. real, b. imaginary, c. in-phase, d. none of the above`, ans:d, 148. The reciprocal of a complex number is, a_____, a. complex number, b. real component only, c. quadrature component only, d. none of above, ans:a, 149. If two complex numbers are equal,, then_____, a. only their magnitudes will be equal, b. only their angles will be equal, c. their in phase and quadrature components, will be separately equal, d.none of above, ans:c, 150. A phasor 2∟180 can be expressed as____, a.j2, b.-j2, c.-2, d.2, ans:c, 151. A current of (3+j4) A is flowing through a, circuit. The magnitude of current is _____, a. 7 A, b. 5 A, c. 1 A, d. 1.33 A, ans:b, 152. The voltage applied in a circuit is given by, 100∟60 volts. It can be written as ____, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 25

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Basic Electrical Engineering, , Multiple Choice Questions, , a. 100∟-60, b.100∟240, c. 100∟-300, d. none of the above, ans:c, , b.50, c.60, d.105, ans:d, , 153. The conjugate of -4+j3 is _____, a. 4-j3, b. -4-j3, c.4+j3, d. none of the above, ans:b, 154. The difference of two conjugate number, results in _____, a. a complex number, b. in-phase component only, c. quadrature component only, d. none of the above, ans:c, 155. The reciprocal of j is ____, a.j, b.-j, c.jxj, d.none of the above, ans:b, 156. Two waves of same frequency have, opposite phase when the phase angle between, them is ___ degrees, a.360, b.180, c.90, d.0, ans: b, 157. Two sinusoidal currents are given by i1 =, 100sin (ωt+π/3) and i2 = 150sin(ωt-π/4). The, phase difference between them is _____, degrees, a.15, , 158. A phasor is _____, a. a line which represents the magnitude and, phase of an alternating quantity, b. a line which represents the magnitude and, direction of an alternating quantity, c. a colored tag or band for distinction between, different phases of a 3 phase supply, d. an instrument used for measuring phases of, an unbalanced 3 phase load, ans:b, 159. A sinusoidal voltage v1 leads another, sinusoidal voltagev2 by 180 degrees. Then ____, a. voltage v2 leads voltage v1 by 180 degrees, b. both voltage have their zero values at the, same time, c. both voltage have their peak values at the, same time, d. all of above, ans:d, 160. If A = 10∟45 and B = 5∟15, then the, value of A/B will be___, a.50∟60, b.2∟60, c. 2∟-30, d.2∟30, ans:d, 161. The length of a phasor in a phasor diagram, normally represents the ………… value of the, alternating quantity, a. rms or effective, b. average, c. peak, d. none of these, ans:a, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 26

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Basic Electrical Engineering, , Multiple Choice Questions, , 162. The two quantities are said to be in phase, with each other when, a. the phase difference between two quantities, is zero degree or radian, b. each of them pass through zero values at the, same instant and rise in the same direction, c. each of them pass through zero values at the, same instant but rises in the opposite directions, d. either (a) or (b), ans:d, 163. The phase difference between the two, waveforms can be compared only when they, a. have the same frequency, b. have the same peak value, c. have the same effective value, d. are sinusoidal, ans:a, 164. The phasor diagram for alternating, quantities can be drawn if they have ………, waves, a. rectangular, b. sinusoidal, c. triangular, d. any of these, ans:b, , Sinhgad College of Engineering, Pune-41, , Telegram - Join @SPPUBtech, , Page 27

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UNIT NO: 3 SINGLE PHASE AC CIRCUIT (PART A), 1. The power factor at resonance in R-L-C series circuit is, a. Zero, b. 0.08 lagging, c. 0.8 leading, d. Unity, Answer: d, 2. In a R-L-C circuit, a. Power is consumed in resistance and is equal to IR, b. Exchange of power takes place between inductor and supply line, c. Exchange of power takes place between capacitor and supply line, d. All above are correct, Answer: d, 3. In an AC. circuit, a low value of kVAR compared with kW indicates, a. Low efficiency, b. High power factor, c. Unity power factor, d. Maximum load current, Answer: b, 4. The power factor of a D.C. circuit is always, a. Less than unity, b. Unity, c. Greater than unity, d. Zero, Answer: b, 5. Which triangles are used in series ac circuit?, a. Voltage triangle, b. Impedance triangle, c. power triangle, d. all of the above, Answer: d, 6. The product of apparent power and cosine of the phase angle between circuit voltage and current, is a. True power, b. Reactive power, c. Volt-amperes, d. Instantaneous power, Answer: a, 7. In a series resonant circuit, the impedance of the circuit is, a. Minimum, b. Maximum, , Telegram - Join @SPPUBtech

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c. Zero, d. None of the above, Answer: a, 8. In a circuit containing R, L and C, power loss can take place in, a. C only, b. L only, c. R only, d. All above, Answer: c, 9. Which of the following refers to a parallel circuit?, a. The current through each element is same, b. The voltage across element is in proportion to it's resistance value, c. The equivalent resistance is greater than any one of the resistors, d. The current through any one element is less than the source current, Answer: d, 10. A sine wave has a frequency of 50 Hz. Its angular frequency is _______, radian/second. a. 100 π, b. 50 jt, c. 25 JT, d. 5 π, Answer: a, 11. The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the, circuit is, a. 4 kVAR, b. 6 kVAR, c. 8 kVAR, d. 16 kVAR, Answer: b, 12. The net power in a series R-C circuit is, a. Zero, b. Positive, c. Negative, d. None of these, Answer: b, 13. The two alternating quantities could be added by constructing, a. Squares, b. Parallelograms, c. Rhombus, d. Trapeziums, Answer: b, , Telegram - Join @SPPUBtech

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14. The power factor of a series RL ac circuit is given by, a. XL/R, b. R/XL, c. R/Z, d. Z/R, Answer: c, 15. The low power factor of an ac circuit means that, a. it causes less voltage drop in the line, b. it draws more active power, c.it draws less line current, d. it draws more reactive power, Answer: d, 16. The impedance of circuit is given by 15.5∠-30 Ω. It means that the circuit is, a. capacitive, b. inductive, c. purely resistive, d. none of the above, Answer: c, 17. In RLC series circuit, the inductive reactance is 10 Ω and capacitive reactance is 15 Ω. The total reactance of the, circuit is, a. 25 Ω, b. 18.03 Ω, c. 5 Ω, d. 1.5 Ω, Answer: c, 18. In series RL circuit, R = 5 Ω, XL = 10 Ω and XC = 15 Ω. If this circuit is connected to a voltage source v = 100, sin (314t + 30) V, the rms value of the current will be, a. 14.14 A, b. 10 A, c. 5 A, d. 3.33 A, Answer : b, 19. An alternating voltage of 80+j60 V is applied to a circuit and the current flowing is 4-j2 A. Find impedance of, circuit., a. 22.37 Ω, b. 23.27 Ω, c. 21.88 Ω, d. 27.22 Ω, Answer: a, , Telegram - Join @SPPUBtech

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20. An alternating voltage of 80+j60 V is applied to a circuit and the current flowing is 4-j2 A. Find power factor of, circuit., a. 0.5 lag, b. 0.447 lead, c. 0.447 lag, d. none of the above, Answer: c, 21. The voltage applied to a circuit is e =100 sin (ωt+30) and the current flowing in the circuit is i = 15 sin (ωt+60)., Determine impedance of the circuit., a. 6.67 Ω, b. 5.57 Ω, c. 7.67 Ω, d. 1.67 Ω, Answer: a, 22. The voltage applied to a circuit is e =100 sin (ωt+30) and the current flowing in the circuit is i = 15 sin (ωt+60)., Determine resistance of the circuit., a. 6.67 Ω, b. 5.77 Ω, c. 7.67 Ω, d. 1.67 Ω, Answer: b, 23. A resistor of 20 Ω, inductor of 0.005 H and capacitor of 50μF are connected in series. A supply voltage 230 V,, 50 Hz is connected across the series combination. Calculate inductive reactance., a. 16.67 Ω, b. 15.71 Ω, c. 17.67 Ω, d. 14.67 Ω, Answer: b, 24. A resistor of 20 Ω, inductor of 0.005 H and capacitor of 50μF are connected in series. A supply voltage 230 V,, 50 Hz is connected across the series combination. Calculate capacitive reactance., a. 53.67 Ω, b. 55.71 Ω, c. 63.67 Ω, d. 57.67 Ω, Answer : c, 25. Two impedances Z1 = 40∠30 and Z2 = 30∠60 are connected in series across a single phase 230 V, 50 Hz, supply. Calculate the current drawn, a. 4.3 A, b. 2.3 A, c. 3.4 A, d. 5.0 A, , Telegram - Join @SPPUBtech

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Answer: c, 26. A coil having a impedance of 50.39∠7.16 is connected in parallel with capacitor having impedance of, 127.32∠-90. If supply voltage is 200 V, single phase, 50 Hz. Calculate current in the coil. a. 4.47∠7.16 A, b. 5.57∠8.16 A, c. 4.97∠90 A, d. 3.97∠-7.16 A, Answer: d, 26. A coil having a impedance of 50.39∠7.16 is connected in parallel with capacitor having impedance of, 127.32∠-90. If supply voltage is 200 V, single phase, 50 Hz. Calculate current in the capactor. a. 4.47∠90 A, b. 5.57∠8.17 A, c. 4.97∠90 A, d. 1.57∠90 A, Answer: d, 27. An impedance of (7+j5) Ω is connected in parallel with another impedance of (10-j8) Ω across a 230 V, 50, Hz supply. Calculate admittance of the circuit., a. 0.16∠-7.04 mho, b. 0.16∠7.04 mho, c. -0.16∠7.04 mho, d. none of the above, Answer: b, 28. Resonance occurs in series RLC circuit if following condition is satisfied., a. XL>XC, b. XL<XC, c. XL=XC, d. XL≠XC, Answer: c, 29. Current of circuit at resonance is, a. Maximum, b. Minimum, c. Unity, d. zero, Answer: a, 30. A series RLC circuit has following parameter values: R = 10 Ω, L = 0.01 H and C = 100 μF. Calculate, resonant frequency., a. 159.15 Hz, b. 169.15 Hz, a. 179.15 Hz, a. 150.15 Hz, Answer: a, , Telegram - Join @SPPUBtech

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Basic Electrical Engineering, , Multiple Choice Questions, , Unit IV, Part (a) :SINGLE PHASE TRANSFORMER, 1. A transformer is used to___________, a. change ac voltage to dc voltage, b. change dc voltage to ac voltage, c. step up or step down dc voltages, d. step up or step down ac voltages, ans: d, 2. The two windings of a transformer, are__________, a. conductively linked, b. inductively linked, c. not linked at all, d. electrically linked, ans: b, 3.The magnetically operated device that can, change values of voltage, current, and, impedance without changing frequency is, the____________, a. Motor, b. Generator, c. Transformer, d. Transistor, ans:c, 4. The transformer winding across which the, supply voltage applied is called the _____, winding., a. Primary, b. Secondary, c. Tertiary, d. Tapped, ans:a, 5. The transformer winding which is connected, to the load is called the_______ winding., a. Primary, b. Secondary, c. Tertiary, , d. Tapped, ans:b, 6. If supply frequency of a transformer, increases, the secondary output voltage of the, transformer____, a. Decreases, b. increases, c. remains same, d. decreases slightly, ans:b, 7. The horizontal and vertical portions of, transformer magnetic core are called, as_________, a. Limb, yoke, b. Yoke, limb, c. Winding, Yoke, d. Winding, Limb, ans:b, 8. The principle of working of transformer is, based on ________, a. Static induction, b. Mutual induction, c. Dynamic induction, d. Self induction, ans:b, 9. Transformer is used to change values, of__________, a. Frequency, b. Voltage, c. Power, d. Power factor, ans:b, 10. The path of the magnetic flux in transformer, should have __________, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 1

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Basic Electrical Engineering, , Multiple Choice Questions, , a. Low resistance, b. Low reluctance, c. High reluctance, d. High conductivity, ans:b, , b. Toroid, c. H core, d. tape wound, ans:a, , 11. Electrical power is transformed from one, coil to other coil in transformer_________, a. Physically, b. Electrically, c. Magnetically, d. Electromagnetically, ans:d, , 16. The concentric cylindrical winding is used, for__________, a. Core type transformer, b. Shell type transformer, c. Berry type transformer, d. None of these, ans:a, , 12. A transformer operates___________, a. Always at unity power factor, b. At power factor depending on load, c. Has its own power factor, d. At power factor below particular value, ans: b, , 17.The sandwich type winding, for___________, a. Core type transformer, b. Berry type transformer, c. Shell type transformer, d. None of these, ans:c, , 13. The laminations of transformer core are, made up from__________, a. Low carbon steel, b. Silicon sheet steel, c. Nickel alloy steel stamping, d. Chrome sheet steel, ans:b, , 18. Silicon steel is used for transformer, core__________, a. To reduce hysteresis loss, b. To reduce eddy current loss, c. To reduce both losses, d. None of these, ans:a, , 14.The material used for construction of, transformer core should have___________, a. Low permeability & high hysteresis loss, b. Low permeability & low hysteresis loss, c. High permeability & high hysteresis loss, d. high permeability & low hysteresis loss, ans:d, , 19. What is common in two windings of, transformer?, a. Electric current, b. Magnetic circuit, c. Winding wire guage, d. None of these, ans:b, , 15. Most transformer cores are not made from, a solid piece of metal. Instead, they are, assembled from many thin sheets of metal. This, type of construction is called__________, a. Laminated, , 20. The main function of transformer iron core, is to__________, a. Provide strength to the winding, b. To decrease hysteresis loss, c. Decrease the reluctance of magnetic path, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , is used, , Page 2

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Basic Electrical Engineering, , Multiple Choice Questions, , d. Reduce eddy current loss, ans:c, , d. Auto, ans:a, , 21. The emf induced in the primary of a, transformer___________, a. is in phase with the flux, b. lags behind the flux by 90 degree, c. leads the flux by 90 degree, d. is in phase opposition to that of flux, ans:b, , 26. Any transformer flux that does not follow, the core and escapes into the surrounding air is, called____, a. magnetizing flux, b. coupling flux, c. leakage flux, d. reactance flux, ans:c, , 22.The, transformer, turns, ratio, determines_____________, a. the ratio of primary and secondary voltages, b. the ratio of primary and secondary currents, c. The resistance on other side, d. all of the above, ans:a, 23. Turns ratio of single phase transformer is, given as__________, a. N2/N1, b. N1/N2, c. (N1xN2)/N1, d. (N1xN2)/N2, ans:b, 24. A transformer in which the secondary, voltage is more than the primary voltage is, called a _____ transformer, a. step-down, b. step-up, c. Isolation, d. Auto, ans:b, 25. A transformer in which the primary voltage, is more than the secondary voltage is called a, _____ transformer., a. step-down, b. step-up, c. Isolation, , 27. A transformer that does not isolate the, output from the input is called, _____, transformer, a. Distribution, b. step-up, c. Auto, d. Control, ans:c, 28. Ideal transformer assumptions do not, include____________, a. Zero reactance of the winding, b. Zero resistance of the winding, c. No leakage flux, d. No saturation of the core, ans:a, 29.The efficiency of the transformer is normally, is normally in the range of____________, a. 50 to 70%, b. 60 to 75 %, c. 80 to 90 %, d. 90 to 98%, ans:d, 30. The resistance of low voltage side of, transformer________, a. Is equal to resistance of its high voltage side, b. Is more than its resistance on high voltage, side, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 3

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Basic Electrical Engineering, , Multiple Choice Questions, , c. Is less than its resistance on high voltage side, d.0, ans:c, 31. Eddy current losses in transformer core are, reduced by_________, a. Increasing the thickness of laminations, b. Decreasing the thickness of laminations, c. Decreasing the air gap in magnetic circuit, d. Using wire of higher guage for winding, ans:b, 32. A good transformer oil should be absolutely, free from__________, a. Sulpher, b. Alkalies, c. Moisture, d. All of the above, ans:c, 33. Single phase core type, has__________, a. One magnetic path, b. Two magnetic paths, c. No magnetic path, d. None of these, ans: a, , transformer, , 34. Single phase shell type transformer, has__________, a. One magnetic path, b. Two magnetic paths, c. No magnetic path, d. None of these, ans:b, 35. Natural cooling is better in_________, a. Core type transformer, b. Shell Type transformer, c. Both A& B, d. Berry type transformer, ans:a, , 36. EMF equation for single phase transformer, is________, a. E= 4.44 Φm A f N, b. E= 4.44 Bm A N, c. E= 4.44 BmfN, d. E= 4.44 ΦmfN, ans:d, 37. Transformation ratio(K) of transformer, is_________, a. N2/N1, b. E1/E2, c. I2/I1, d. V1/V2, ans:a, 38., For, Isolation, transformer, transformation ratio(K) is_________, a.0, b. Greater than 1, c. Less than 1, d.1, ans:d, , the, , 39. In step up transformer the transformation, ratio (K) is_____________, a. Greater than 1, b.1, c. Less than 1, d.0, ans: a, 40. In step down transformer, transformation ratio (K) is__________, a. Greater than 1, b.1, c. Less than 1, d.0, ans:c, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , the, , Page 4

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Basic Electrical Engineering, , Multiple Choice Questions, , 41. The primary and secondary voltages in, transformer are___________, a. Always in Phase, b. 1800 out of phase, c. 900 out of phase, d. 300 or 600 out of phase, ans:b, , 46. Transformer oil is used in transformer to, provide_______, a. Cooling and insulation, b. Cooling and lubrication, c. Insulation and lubrication, d. Insulation, cooling and lubrication, ans:a, , 42. The induced emf in transformer secondary, depends on__________, a. Maximum flux in core, b. Frequency, c. No of turns on secondary, d. all of the above, ans:d, , 47., What, is, the, typical, autotransformer____________?, a. Toy transformer, b. Control transformer, c. Variable transformer, d. Isolating transformer, ans:c, , 43. Transformer rating usually, in____________, a.kW, b.kVA, c. kV, d. kWh, ans:b, , expressed, , 48. In any transformer the voltage per turn in, primary and secondary remains____________, a. Always different, b. Always the same, c. Always in ratio of K, d. Sometimes same, ans:b, , 44. In a transformer if secondary turns are, doubled, at the same time primary voltage is, reduced by half, the secondary voltage, will_________, a. Be halved, b. Not change, c. Be four times, d. Be reduced to quarter, ans:b, 45. The no load current in terms of full load, current is usually________, a. 1 to 3%, b. 3 to 9 %, c. 9 to 12%, d. 12 to 20%, ans:a, , 49. Full load copper loss in a transformer is 400, Watt. At half load, copper losses will, be___________, a. 400 Watt, b. 100 Watt, c. 200 Watt, d. 50 Watt, ans:b, 50. A transformer is working with its maximum, efficiency. If the iron losses are 500 W, the, copper loss will__________, a. 300 W, b. 350 W, c. 250 W, d. 500 W, ans:d, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , use, , of, , Page 5

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Basic Electrical Engineering, , Multiple Choice Questions, , 51. If we increase the flux density in case, transformer_______________, a. The size of transformer will reduce, b. The distortion in transformer will reduce, c. Hysteresis and eddy current losses will reduce, d. None of these will be true, ans:a, 52. The direct loading test is performed on, transformer to find its____________, a. Regulation, b. Efficiency, c. Both, d. None of these, ans:c, 53. The regulation of transformer is calculated, as_________, , b., c., d., ans:a, 54. The efficiency of single phase transformer is, calculated as_____________, , b., c., d., , 56. For 100 kVA, 11000V/110V single phase, transformer, the secondary full load current, is________, a. 90.90 Amp, b. 9090.9 Amp, c. 909.0 Amp, d. 9.09 Amp, ans:c, 57. The disadvantage of auto transformer, is______________, a. No separation between primary & secondary, b. Size is more than normal transformer for, same rating, c. More costlier than normal transformer, d. All, ans:d, , a., , a., , 55. For 100 kVA, 11000V/110V single phase, transformer, the primary full load current, is____________, a. 909.09 Amp, b. 90.90 Amp, c. 9.09 Amp, d. 9090.9 Amp, ans:c, , ∅, ∅, ∅, ∅, ∅, , 58. In a transformer the voltage regulation will, be near to zero when it operates, at____________, a. unity p.f., b. leading p.f., c. lagging p.f., d. full load., ans:b, 59. A transformer steps up voltage by a factor, of 100. The ratio of current in the primary to, that in secondary_______________, a.1, b.100, , ∅, ∅, ∅, , ans:a, Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 6

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Basic Electrical Engineering, , Multiple Choice Questions, , c.0.01, d.0.1, ans:b, 60. An ideal transformer, change______________, a. Voltage, b. Power, c. current, d. None of these, ans:b, , ans:a, , does, , not, , 61. The flux in transformer core____________, a. increases with load, b. decreases with load, c. remains constant irrespective of load, d. none of these, ans:c, 62. Efficiency of transformer is maximum, when___________, a. transformer is unloaded, b. copper losses is equal to iron losses, c. eddy current losses are equal to hysteresis, losses, d. it is maximally loaded, ans:b, 63. If the supply frequency in transformer is, doubled, then_________, a. hysteresis loss also doubles, b. eddy current loss also doubles, c. iron losses doubles, d. copper losses doubles, ans:a, 64. Hysteresis loss in transformer depends, on__________, a. both voltage and frequency, b. voltage alone, c. frequency alone, d. none of these, , 65., Eddy, current, loss, on_____________, a. both current and frequency, b. current alone, c. frequency alone, d. none of these, ans:a, , depends, , 66.The flux involved in EMF equation of a, transformer has______________, a. RMS Value, b. Average Value, c. Total Value, d. maximum Value, ans:d, 67. A transformer has maximum efficiency at ¾, of full load. The ratio of its iron loss and full load, copper loss is_________, a. 16/9, b. 4/3, c. 3/4, d. 9/16, ans:d, 68. If primary of the transformer is connected, to dc supply, then______, a. Primary draws small current, b. primary leakage reactance is increased, c. core losses are increased, d. primary may burn out, ans:d, 69. For an ideal transformer the windings, should have____________, a. maximum resistance on primary side and, least resistance on secondary side, b. least resistance on primary side ans, maximum resistance on secondary side, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 7

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Basic Electrical Engineering, , Multiple Choice Questions, , c. equal resistance on primary and secondary, side, d. no ohmic resistance on either side, ans:d, 70. The full load copper and iron loss of a, transformer are 6400 W and 5000 W, respectively. The copper loss and iron loss at, half load will be respectively______, a. 3200 W and 2500 W, b. 3200 W and 5200 W, c. 1600 W and 1250 W, d. 1600 W and 5000 W, ans:d, 71. A transformer does not raise or lower the, voltage of DC supply because________, a. there is no need to change the DC voltage, b. DC circuit has more losses, c. Faradays law of Electromagnetic Induction, are not valid since the rate of change of flux is, zero, d. none of these, ans:c, 72. Primary winding of a transformer, _____________, a. is always low voltage winding, b. is always high voltage winding, c. could either be a low or high voltage winding, d. none of these, ans:c, 73. Which winding of a transformer has more, number of turns_______________, a. Low voltage winding, b. High voltage winding, c. Primary winding, d. secondary winding, ans:b, , 74. In a given transformer for a given applied, voltage, which losses remain constant, irrespective of change in load___________, a. Friction and windage loss, b. copper loss, c. hysteresis and eddy current loss, d. none of these, ans:c, 75. Main advantage to use autotransformer, over two winding transformer____________, a. Hysteresis losses are reduced, b. savings in winding material, c. copper losses are negligible, d. Eddy current losses are totally eliminated, ans:b, 76. An ideal transformer is one which has, _____________, a. no losses and magnetic leakage, b. interleaved primary and secondary winding, c. a common core for its primary and secondary, d. core of stainless steel and winding of pure, copper material, ans:a, 77. In a practical transformer core losses, remains constant from no load to full load, because__________, a. value of transformation ratio remains, constant, b. permeability of transformer core remains, constant, c. core flux remains practically constant, d. primary and secondary voltage remains, constant, ans.c, 78.The transformer laminations are insulated, from each other by_____________, a. mica strip, b. thin coat of varnish, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 8

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Basic Electrical Engineering, , Multiple Choice Questions, , c. paper, d. any one of these, ans:b, 79. In transformer resistance between primary, and secondary should be_____________, a. zero, b. 10 ohm, c. 1000 ohm, d. infinity, ans:d, 80. A good voltage regulation of transformer, means___________, a. output voltage fluctuations from no load to, full load is least, b. output voltage fluctuations with power factor, is least, c. difference between primary and secondary, voltage is least, d. difference between primary and secondary, voltage is maximum, ans:a, 81. Negative voltage regulation is indicative that, the load is_____________, a. Capacitive only, b. inductive only, c. inductive or resistive, d. none of these, ans:a, 82. The size of the transformer core depend, on___________, a. frequency, b. area of the core, c. flux density of the core material, d. (a) and (b) both, ans:d, 83., A, shell, type, _______________, , transformer, , a. high eddy current losses, b. reduced magnetic leakage, c. negligible hysteresis loss, d.none of these, ans:b, 84. Deduction in core losses and increase in, permeability are obtained with transformer, employing______, a. core built up of laminations of cold rolled, grain oriented steel, b. core built up of laminations of hot rolled steel, c. either a or b, d. none of these, ans: c, 85. Losses which occur in rotating electric, machine and do not occur in transformers, are____________, a. friction and windage losses, b. magnetic losses, c. hysteresis and eddy current losses, d. copper losses, ans:a, 86. Which of the following loss in a transformer, is zero even at full load__________, a. core loss, b. friction loss, c. eddy current loss, d. Hysteresis loss, ans:b, 87. The noise produced by transformer is, termed as _______________, a. zoom, b.hum, c. ringing, d. buzz, ans:b, , has, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 9

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Basic Electrical Engineering, , Multiple Choice Questions, , 88. Part of the transformer which is most, subject to damage from overheating, is______________, a. iron core, b. copper winding, c. insulation of the winding, d. transformer tank, ans:c, 89.In a step down transformer, there is a, change of 15A in the load current. This results in, change of supply current of_____________, a. less than 15 A, b. more than 15 A, c.15A, d. none of these, ans:a, 90. As per the name plate of transformer, the, secondary normal voltage is 220V. Which of the, following statement about it is correct?_______, a. 220V is no load voltage, b. The no load voltage is more than 220V, c. The secondary voltage increases with, increase in load, d. At a load which draws the rated current &, the voltage becomes less than 220V., ans:b, 91.In which of the following transformer, part, of the primary winding serves as the secondary, winding__, a. Potential transformer, b. Auto transformer, c. Step up transformer, d. None of these, ans:b, 92. The rating of the transformer is given in kVA, instead of kW because__________, a. kVA is fixed whereas kW depends on load pf, b. load power factor is often not known, , c. it has become customary, d. total transformer loss depends on VA, ans:b, 93. Increase in secondary current of, transformer brings about increase in primary, current . This is possible because___________, a. primary and secondary windings are, capacitively coupled., b. primary and secondary windings are, inductively coupled, c. primary and secondary windings are, conductively coupled, d. none of these, ans:b, 94. Transformer for constant voltage, application is considered good if its voltage, regulation is_________, a. low, b. high, c. zero, d. none of these, ans:c, 95. Transformer action needs that the magnetic, flux linking with the winding must, be_____________, a. constant, b. pulsating, c. alternating, d. none of these, ans:c, 96. Low voltage windings are placed next to the, core to reduce_____________, a. Hysteresis loss, b. eddy current loss, c. insulation requirement, d. copper loss, ans:c, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 10

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Basic Electrical Engineering, , Multiple Choice Questions, , 97. The relation between the primary and, secondary ampere turns of transformer ---------a. exactly equal, b. approximately equal, c. primary mmf larger than secondary mmf, d. primary mmf smaller than secondary mmf, ans:a, 98. Positive voltage regulation occurs in case of, transformer for______________, a. capacitive load, b. resistive load only, c. inductive load only, d. either inductive or resistive load, ans:d, 99. Cooling of the transformer is required so as, to_____________, a. increase the efficiency, b. to reduce the losses, c. to reduce humming, d. to dissipate the heat generated in the, winding, ans:d, 100. The transformer efficiency will be, maximum at a power factor of ____________, a. 0.8pf lead, b. unity, c. 0.8 lag, d. 0.5 lag or lead, ans:b, 101. The regulations of two transformers are (i), 3% and (ii) 97%. The one with better regulation, is______, a. second, b. first, c. both are same, d. depends on loading, ans:b, , 102. A transformer has 2600 V on primary side, and 260 V on secondary side. The, transformation ratio is_, a.10, b.5, c.0.1, d.9, ans:c, 103. If the copper loss of a transformer at 70%, of full load is 200 W. The full load copper loss is, ________, a. 200 W, b. 285.71 W, c.408.16W, d. none of these, ans:c, 104. A transformer having 1000 primary turns is, connected 250 V ac supply. For a secondary, voltage of 400 volt, the no of secondary turns, should be________, a.1600, b.250, c.400, d.1250, ans:a, 105. If Copper loss of a transformer at 7/8th of, the full load is 4900W. Then its full load copper, loss is____, a.5600, b.6400, c.375, d.429, ans:b, 106. At relatively light loads, the transformer, efficiency is low because__________, a. secondary output is low, b. transformer losses are high, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 11

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Basic Electrical Engineering, , Multiple Choice Questions, , c. fixed loss is high in proportion to the output, d. copper loss is small., ans:c, 107.A 3000 V/200 V, 50 Hz, single phase, transformer is built on a core having an, effective cross sectional area of 120 cm2 and 60, turns on the secondary winding. The value of, maximum flux density___, a.1.25 Tesla, b.1.52 Tesla, c.1.3 Tesla, d.none of the above, ans:a, 108. A 3000 V/200 V, 50 Hz, single phase, transformer is built on a core having an, effective cross sectional area of 120 cm2 and 60, turns on the secondary winding. The number of, turns on the high voltage winding________, a. 600 turns, b. 900 turns, c. 300 turns, d. 450 turns, ans:b, 109. A 3300 V/250 V, 50 Hz, single phase, transformer has to be worked at a maximum, flux density of 1.1 wb/m2 in the core. The, effective cross sectional area of the core is 145, cm2. The no of primary turns___, a. 930 turns, b. 950 turns, c. 932 turns, d. 923 turns, ans:c, 110. A 3300 V/250 V, 50 Hz, single phase, transformer has to be worked at a maximum, flux density of 1.1 web/m2 in the core. The, , effective cross sectional area of the core is 145, cm2. The no of secondary turns___, a.71 turns, b.75 turns, c.932 turns, d.923 turns, ans:a, 111. A 80 kVA, 6000 V/ 400 V, 50 Hz single, phase transformer has 80 turns on the, secondary winding. The value of maximum flux, in the core________, a.25.22mwb, b.22.52mwb, c.52.22mwb, d. none of these, ans:b, 112. A 6600 V/220 V, 50 Hz, step down single, phase transformer has 1500 turns on its, primary side. If its maximum flux density is 1.2, Tesla, then the effective cross sectional area of, core is _____, a.16.516  10–3 m2, b.61.516  10–3 m2, c.26.516  10–3 m2, d.62.516  10–3 m2, ans:a, 113. A 10 kVA, 3300/240 V, single phase, 50 Hz, transformer has a core area of 300 sq. cm. The, flux density is 1.3 tesla. The primary full load, current is ___________, a. 3.03 amp, b. 33.03 amp, c. 30.3 amp, d. 0.303 amp, ans:a, 114.A transformer is rated at 90 kVA, at full, load its copper losses is 1100 W and its iron, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 12

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Basic Electrical Engineering, , Multiple Choice Questions, , losses is 950 W. The efficiency at full load for, unity power factor is___________, a. 99%, b.96%, c.97.77%, d. none of these, ans:c, , efficiency at 75% of full load and unity power, factor__________, a.98.13%, b.98.73%, c.99%, d. none of these, ans:b, , 115. A transformer is rated at 90 kVA, at full, load its copper losses is 1100 W and its iron, losses is 950 W. The efficiency at 60% of full, load for 0.8 lagging power factor is___________, a.96.97%, b.96%, c.98%, d. none of these, ans:a, , 117: The no load voltage at the secondary, terminals of single phase transformer is, observed as 230 volt. When the transformer is, loaded, the voltage on secondary side has, reduced to 224 volt. Then the % regulation of, transformer for that loading is_______, a.2.6%, b.2.67%, c.0%, d. none of these, ans:a, , 116. A 500 kVA transformer has iron loss of 2, kW and full load copper losses of 5 kW. The, , Sinhgad Institute of Technology Lonavala, , Telegram - Join @SPPUBtech, , Page 13

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Sinhgad College of Engineering, Basic Electrical Engineering, Unit: 05 DC Circuits, 1. A passive network, a. Has no current source, b. Has no e.m.f. source., c. Has neither of the above, d. Has either of the above, Ans: c, 2. In any linear network, the elements like, inductor, resistor and capacitor always…, a. Exhibit changes due to change in, temperature, b. Exhibit changes due to change in voltage, c. Exhibit changes due to change in time, d. Remains constant irrespective of change, in temperature, voltage and time, Ans: d, , 3. Which law plays a significant role in, the loop analysis of the network?, a. KCL, b. KVL, c. Law of Superposition Theorem, d. None of the above, Ans: b, , 4. Which is the correct sequential order of, steps to be undertaken while applying, Thevenin’s theorem?, A. Calculation of Thevenin’s equivalent, voltage, B. Removal of branch impedance through, which required current is to be estimated, C. Estimation of equivalent impedance, between two terminals of the branch, D. Estimation of branch current by, schematic representation of Thevenin’s, equivalent circuit, a. A, C, B, D, b. B, A, C, D, , c. D, A, C, B, d. B, C, D, A, Ans: b, , 5. A network which contains one or more, than one source of e.m.f. is known as, a. Linear network, b. Non-linear network, c. Passive network, d. Active network, Ans: d, , 6. In non-linear network does not satisfy, a. Superposition condition, b. Homogeneity condition, c. Both homogeneity and superposition, condition, d. Homogeneity, superposition and, associative condition, Ans: d, , 7. A closed path made by several, branches of the network is known as, a. Branch, b. Loop, c. Circuit, d. Junction, Ans: b, , 8. A network consists of linear resistors, and ideal voltage source. If the value of, the resistors are doubled then voltage, across each resistor is, a. Halved, b. Doubled, c. Increased four lines, d. Not changed, Ans: d, , Follow @PuneEngineers | Telegram

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9. Which of the following is an active, element in a circuit?, a. Current source, b. Resistance, c. Inductance, d. Capacitance, Ans: a, , 10. Which of the following is not a, bilateral element?, a. Constant current source, b. Resister, c. Inductor, d. capacitor, Ans: a, , 11. The elements which are not capable of, delivering energy by its own are known as, a. Unilateral elements, b. Nonlinear elements, c. Passive elements, d. Active elements, Ans: c, , 12. To neglect a voltage source, the, terminals across the source are, a.. Open-circuited, b. Short-circuited, c. Replaced by some resistance, d. Replaced by inductor, Ans: b, , 13. For determining the polarity of a, voltage drop across a resistor, it is, necessary to know the, a.. Value of resistor, b. Value of current, c. Direction of current flowing through the, resistor, d. Value of e.m.f. in the circuit, Ans: c, , 14. Which of the following is the passive, element?, a. Capacitance, b. Ideal current source, , c. Ideal voltage source, d. All of the above, Ans: a, , 15. A terminal where three or more, branches meet is known as, a.. Node, b. Terminus, c. Combination, d. Anode, Ans: a, , 16. Ideal voltage source have, a.. Zero internal resistance, b. Infinite internal resistance, c. Low value of current, d. Large value of e.m.f., Ans: a, , 17. Ideal current source have, a.. Zero internal resistance, b. Infinite internal resistance, c. Low value of voltage, d. Large value of current, Ans: b, , 18. Star circuit has element of resistance, R/2. The equivalent delta elements will be, a.. R/6, b. 3/2 R, c. 2R, d. 4R, Ans: b, , 19. A delta circuit has each element of, value R/2.The equivalent elements of the, star circuit will be, a.. R/6, b. R/3, c. 2R, d. 3R, Ans: a, , Follow @PuneEngineers | Telegram

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20. A practical current source is, represented by, a.. A resistance in series with an ideal, current source, b. A resistance in parallel with an ideal, current source, c. A resistance in parallel with an ideal, voltage source, d None of the above, Ans: b, , 21. The terminals connected to the source, are................... if a current source is to be, neglected, a. Open-circuited, b. Short-circuited, c. Replaced by a capacitor, d. Replaced by a source resistance, Ans: a, , 22. Which of the following statements is, incorrect?, a.. Resistance is a passive element, b. Inductor is a passive element, c. Current source is a passive element, d. Voltage source is an active element, Ans: c, , 23. Kirchhoff's current law is applicable, to only, a. Junction in a network, b. Closed loops in a network, c. Electric circuits, d. Electronic circuits, Ans: a, , 24. Kirchhoff's current law states that, a. Net current flow at the junction is positive, b. Algebraic sum of the currents meeting at, the junction is zero, c. No current can leave the junction without, some current entering it, d. Total sum of currents meeting at the, junction is zero, Ans: b, , 25. Kirchhoff's voltage law is related to, a.. Junction cards, b. Battery e.m.f’s, c. IR drops, d. Both B and C, Ans: d, , 26. According to Kirchhoff's voltage law,, the algebraic some of all IR drops and, e.m.fs. in any closed loop of a network is, always, a.. Negative, b. Positive, c. Determined by battery e. m. f’s., d. Zero, Ans: d, , 27. The circuit having same properties in, either direction is known as ....... circuit, a. Bilateral, b. Unilateral, c. Irreversible, d. Reversible, Ans: a, , 28. The circuit having different properties, in either direction is known as ........circuit, a. Bilateral, b. Unilateral, c. Irreversible, d. Reversible, Ans: d, , 29. Two ideal voltage sources of unequal, output voltages cannot be placed in........, a. Series, b. Parallel, c. Both series and parallel, d. None of the above, Ans: b, , 30. Which type of networks allow the, physical separability of the network, elements (resistors, inductors &, capacitors) for analysis purpose?, , Follow @PuneEngineers | Telegram

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a. Lumped Networks, b. Distributed Networks, c. Unilateral Networks, d. Bilateral Networks, Ans: a, , 31. Which type of networks don’t allow, the physical separability of the network, elements (resistors, inductors &, capacitors) for analysis purpose?, a. Lumped Networks, b. Distributed Networks, c. Unilateral Networks, d. Bilateral Networks, Ans: b, , 32. KCL is based on the fact that, a There is a possibility for a node to store, energy., b There cannot be an accumulation of, charge at a node., c Charge accumulation is possible at node, d Charge accumulation may or may not be, possible., Ans: b, , 33. Relation between currents according, to KCL is, , a 13Ω, b 8.66Ω, c 6.5Ω, d 7.33Ω, Ans: b, , 35. Thevenin’s equivalent circuit consists, of a ___, a. Voltage source in series with a resistor, b. Current source in parallel with a resistor, c. Voltage source in parallel with a resistor, d. Current source in series with a resistor, Ans: a, , 36. Thevenin’s voltage is equal to ___, a Short circuit voltage, b Open circuit current, c Open circuit voltage, d Short circuit current, Ans: b, , 37. What is the expression for the, thevenin’s current if there is an external, resistance of R ohm in series with the, RTh?, a VTh/ITh, b VTh/ (RTh-R), c VTh/ (RTh+R), d VTh/RTh, , a i1=i2=i3=i4=i5, b i1+i4+i3=i5+i2, c i1-i5=i2-i3-i4, d i1+i5=i2+i3+i4, , Ans: c, , Ans: d, , 34. What will be the resistance between B, and C when the network given below is, converted into delta?, , 38. One can find the thevenin’s resistance, simply by replacing all voltage sources by, …….and current sources by ………&, calculating equivalent resistance., a opening, opening, b Shorting, Shorting, c Opening, Shorting, , Follow @PuneEngineers | Telegram

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d Shorting, Opening, Ans: d, , 39. The Superposition principle is obeyed, by ____________, a Linear networks, b Non-linear networks, c Lateral networks, d Nine of the Above, Ans: a, , 40. According to Superposition principle, response in one element is the ………..of, responses by individual sources acting, alone., a Arithmetic Sum, b Algebraic Sum, c Product, d Division, , a 10, b5, c 2.5, d 1.25, Ans: b, , 44. The current flowing in the branches of, a d.c. circuit may be determined using:, a Kirchhoff’s laws, b Lenz’s law, c Faraday’s laws, d Fleming’s left-hand rule, Ans: a, , 45. Which of the following statements is, true, , Ans: b, , 41. Superposition principle states that at a, time __________ source(S) acts., a All the given sources, b Only voltage sources, c Only one source, d Only current sources, Ans: c, , 42. If the voltage-current characteristics, is a straight line through the origin, then, the element is said to be?, a Linear element, b Non-linear element, c Unilateral element, d Bilateral element, , a I5 − I4 = I3 − I2 + I1, b I1 + I2 + I3 = I4 + I5, c I2 + I3 + I5 = I1 + I4, d I1 − I2 − I3 − I4 + I5 = 0, Ans: d, , 46. Which of the following statements is, true, , Ans: a, , 43. The voltage across R1 resistor in the, circuit shown below is?, , a. E1 + E2 + E3 = Ir1 + Ir2 + Ir3, b. E2 + E3 − E1 − I(r1 + r2 + r3) = 0, c. I(r1 + r2 + r3) = E1 − E2 − E3, d. E2 + E3 − E1 = Ir1 + Ir2 + Ir3, Ans: c, , 47. Ra is resistance at A, Rb is resistance, at B, Rc is resistance at C in star, , Follow @PuneEngineers | Telegram

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connection. After transforming to delta,, what is resistance between B and C?, a. Rc+Rb+Rc*Rb/Ra, b. Rc+Rb+Ra*Rb/Rc, c. Ra+Rb+Ra*Rc/Rb, d. Rc+Rb+Rc*Ra/Rb, Ans: a, , 52. In superposition theorem, when we, consider the effect of one voltage source,, all the other current sources are _____, a Shorted, b Opened, c Removed, d Undisturbed, Ans: b, , 48. Ra is resistance at A, Rb is resistance, at B, Rc is resistance at C in star, connection. After transforming to delta,, what is resistance between A and C?, a. Ra+Rb+Ra*Rb/Rc, b. Ra+Rc+Ra*Rc/Rb, c. Ra+Rb+Ra*Rc/Ra, d. Ra+Rc+Ra*Rb/Rc, , 53. In superposition theorem, when we, consider the effect of one current source,, all the other current sources are _____, a Shorted, b Opened, c Removed, d Undisturbed, , Ans: b, , Ans: b, , 49. Ra is resistance at A, Rb is resistance, at B, Rc is resistance at C in star, connection. After transforming to delta,, what is resistance between A and B?, a. Rc+Rb+Ra*Rb/Rc, b. Ra+Rb+Ra*Rc/Rb, c. Ra+Rb+Ra*Rb/Rc, d. Ra+Rc+Ra*Rc/Rb, , 54. Superposition theorem is valid for __, a. Linear systems, b. Non-linear systems, c. Both linear and non-linear systems, d. Neither linear nor non-linear systems, , Ans: c, , 50. In superposition theorem, when we, consider the effect of one voltage source,, all the other voltage sources are _____, a. Shorted, b. Opened, c. Removed, d. Undisturbed, Ans: a, , 51. In superposition theorem, when we, consider the effect of one current source,, all the other voltage sources are, ____________, a Shorted, b Opened, c Removed, d Undisturbed, Ans: a, , Ans: a, , 55. Superposition theorem does not work, for ________, a. Current, b. Voltage, c. Power, d. Works for all: current, voltage and power, Ans: c, , 56. Thevenin’s resistance is found by, ________, a Shorting all voltage sources, b Opening all current sources, c Shorting all voltage sources and opening, all current sources, d Opening all voltage sources and shorting, all current sources, Ans: c, , 57. In Thevenin’s theorem Vth is, __________, a. Sum of two voltage sources, b. A single voltage source, , Follow @PuneEngineers | Telegram

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c. Infinite voltage sources, d. 0, Ans: b, , 58. An active element in a circuit is one, which _____, Receives energy, Supplies energy, Both receives and supplies energy, None of the above, Ans: b, , 59. A passive element in a circuit is one, which.., Receives energy, Supplies energy, Both receives and supplies energy, None of the above, Ans: a, , 60. A linear circuit is one whose, parameter __, a. Changes with change in current, b. Changes with change in voltage, c. Changes with both voltage and current, d. Do not changes with voltage and current, Ans:d, 61. The superposition theorem is used, when the circuit contains _______, a. A single voltage sources, b. A number of voltage sources, c. Only passive elements, d. None of the above, , a.360 Ω, b.240 Ω, c.180 Ω, d.120 Ω, Ans: a, , 64. The resistor values in wye network, that is equivalent to a delta containing, three 12 kΩ resistor is, a. 2 kΩ, b. 4 kΩ, c. 8 kΩ, d. 36 kΩ, Ans: b, , 65. The superposition theorem applies to, a. Current / Voltage calculations, b. Power calculations, c. Current and power calculations, d. Voltage and power calculations, Ans: a, , 66. Why does the Superposition theorem, not applicable to power?, a. Because it is proportional to square of, current and current is a non-linear function, b. Because it is proportional to square of, voltage and voltage is a non-linear function, c. Both a and b, d. None of the above, Ans: a, , Ans: b, , 62. Star/Delta or Delta/Star technique is, applied to _____network, a. One terminal, b. Two terminal, c. Three terminal, d. None of the above, Ans: c, , 63. The resistor value in delta network, that is equivalent to a wye containing, three 120 Ω resistors is, , Follow @PuneEngineers | Telegram

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Basic Electrical Engineering, , Multiple Choice Questions, UNIT-VI, Work, Power, Energy and Batteries, , 1. Which effect of electrical current is utilized in, thermal systems?, a. Magnetic, b. chemical, c. heating, d. all above, ans: c, 2. As per the Joule’s law the amount of heat, produced is proportional to, a. I.R, b. V.I, c. V.I.t, d. None of above, ans: c, 3. Geyser is a example of which system, a. Mechanical, b. Electrical, c. Thermal, d. None of above, ans: b, 4. Boiling temp. of water is, a.50, b.75, c.100, d.35, ans: c, 5. The amount of heat energy required to, change the temp. of a given substance without, change in the form of the substance is called as, a. Sensible heat energy, b. Latent heat energy, c. Both of above, d. None of above, ans:a, , 6. Which statement is correct?, a.1cal=4.12 J, b.1cal=4.186 J, c.1cal=4.44 J, d.1cal=3.986 J, ans:b, 7. The amount of heat energy required to, change the state of the substance without, change in the temperature is called as, a. Kinetic energy, b. Potential energy, c. Latent heat energy, d. All of above, ans:c, 8. The amount of heat energy obtained by, burning the unit mass of the fuel is called as, a. Molecular value, b. Calorific value, c. Atomic value, d. None of above, ans:b, 9. The unit of “THERMAL ENERGY” is, a. Kilowatt-hour, b. Watt-sec, c. Joule, d. all of above, ans:c, 10. Which effect of electric current is utilized in, electric lamps?, a. Magnetic effect, b. Chemical effect, c. Heating effect, d. All of above, ans:c, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 1

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Basic Electrical Engineering, 11. The heat energy required to convert a body, from solid state to liquid state is called as, a. Latent heat of fusion, b. Latent heat of vaporization, c. Calorific value, d. All of above, ans: a, , Multiple Choice Questions, d. none of above, ans:a, 17. Which relationship is correct, a. P=T.ω, b. P=T/ ω, c. P=T.v d.None of above, ans:a, , 12. The heat energy required to convert liquid, state to gaseous state is called as, a. Latent heat of liquification., b. Latent heat of vaporization, c. both of above, d. None of above, ans: b, , 18. Power is defined as, a. capacity to do the work, b. work done/time, c. work done. time, d. all above, ans:b, , 13. The unit of specific heat capacity is, a. J/Kg, b. J/KgK, c. joules, d. none of above, ans: b, , 19. Energy is defined as, a. work done/time, b. capacity to do the work, c. energy=power x resistance, d. all above, ans:b, , 14. MOTOR-PUMP SET is the example of which, system, a. Electro-mechanical system, b. Electro-chemical system, c. Only electrical system, d. All above, ans: a, , 20. Effective water head of a Hydro-electric, power plant means it’s, a. loss, b. height, c. friction, d. none of above, ans:b, , 15. The unit of force is, a. Newton, b. Joule, c. Newton-metre, d. none of above, ans: a, , 21. Efficiency is the ratio of, a. power and time, b. output and input, c. input and output, d. above all, ans:b, , 16. One metre cube holds a water of, a.1000Kg, b.1000gm, c.1000miligram, , 22. Wind-mill-Generator set is the example of, a. electro-chemical system, b. electro-thermal system, c. mechanical-electrical system, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 2

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Basic Electrical Engineering, d. all above, ans: c, 23. Which relationship is correct?, a. volume=mass. Density, b. volume=mass/density, c. volume=mass + density, d. none of above, ans: a, 24. Potential energy is given as, a. E= m.g.h, b. E=m.g, c. E=m.g.t, d. above all, ans: a, 25. Kinetic energy is given by, a. 𝐸 = 𝑚𝑉, b. 𝐸 = 𝑚𝑉, c. 𝐸 = 𝑚𝑡, d. none of above, ans: a, 26. A 100W electric light bulb is connected to a, 250V supply. The current in the circuit is, a.0.3A, b. 0.4A, c. 1.4A, d. 0.6A, ans: b, 27. A 100W electric light bulb is connected to a, 250V supply. Its hot resistance is, a.625Ω, b.526Ω, c. 62.5Ω, d. 625mΩ, ans:a, 28. 60 μs is equivalent to:, , Multiple Choice Questions, a.0.06s, b. 0.00006s, c. 1000 minutes, d. 0.6 s, ans: b, 29. The current which flows when 0.1 coulomb, is transferred in 10 ms is, a. 1A, b. 10A, c. 10mA, d. 100mA, ans: b, 30. The p.d. applied to a 1 kΩ resistance in, order that a current of 100 μA may flow is, a. 1V, b. 100V, c. 0.1V, d. 10V, ans:c, 31. The power dissipated by a resistor of, 4Ωwhen a current of 5A passes through it is, a. 6.25W, b. 20W, c. 80W, d. 100W, ans:d, 32. Which of the following statements is true?, a. Electric current is measured in volts, b. 200 kΩ resistance is equivalent to 2MΩ, c. An ammeter has a low resistance and must be, connected in parallel with a circuit, d. An electrical insulator has a high resistance, ans:d, 33. A current of 3A flows for 50 hrs through, a6Ωresistor. The energy consumed by the, resistor is:, a.0.9 kWh, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 3

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Basic Electrical Engineering, b.2.7 kWh, c.9 kWh, d.27 kWh, ans:b, 34. What must be known in order to calculate, the energy used by an electrical appliance?, a. voltage and current, b. current and time of operation, c. power and time of operation, d. current and resistance, ans: c, 35. Voltage drop is the, a. maximum potential, b. difference in potential between two points, c. voltage produced by a source, d. voltage at the end of a circuit, ans: b, 36. A 240V, 60Wlamp has a working resistance, of, a. 1400 ohm, b. 60 ohm, c. 960 ohm, d. 325 ohm, ans:c, 37. The energy used by a 1.5kW heater in 5, minutes is:, a. 5 J, b. 450 J, c. 7500 J, d. 450000 J, ans:d, 38. If a current of 5A flows for 2 minutes, the, quantity of charge transferred will, a. 600C, b. 100C, c. 0.6C, d. 60C, , Multiple Choice Questions, ans: a, 39. In what time would a current of 1A transfer, a charge of 30 Coulomb?, a. 45s, b. 30s, c. 65s, d.4s, ans: b, 40. How long must a current of 0.1A flow so as, to transfer a charge of 30 Coulomb?, a. 5 min, b. 5s, c. 50min, d. 50s, ans: a, 41. A force of 4N moves an object 200 cm in the, direction of the force. Work done is, a. 6 J, b. 8 J, c. 4 J, d. 10 J, ans:b, 42. The amount of work done in lifting a mass of, 500 kg to a height of 6min 30 sec …., a. 2943J, b. 0.2943J, c. 29.43J, d. 29.43KJ, ans:d, 43. The power required in lifting a mass of 500, kg to a height of 6m in 30 sec…., a.198J, b. 981W, c.198W d. 981J, ans: b, 44. 0.32mA=. . . . . . μA, a.0.0032, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 4

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Basic Electrical Engineering, b.0.032, c.0.00032, d.320, ans: d, , Multiple Choice Questions, a. 0.5 kWh, b. 4 kWh, c. 2 kWh, d. 0.02 kWh, ans: b, , 45. A portable machine requires a force of 200N, to move it. If the machine is moved through, 20m in 25s, power required is, a. 160kW, b. 1600W, c. 16kW, d.160W, ans: d, 46. Energy provided by a source e.m.f. of 5V, supplying a current of 3A for 10 minutes is, a.9kJ, b. 65J, c. 25kJ, d. 90kJ, ans: a, 47. 450 J of energy are converted into heat in 1, minute. The power dissipated is, a.7.5kW, b.7.5W, c.750W, d. 600W, ans: b, 48. The power rating of a d.c. electric motor, consuming 36 MJ when connected to a 250V, supply for 1 hour is, a. 100W, b.10W, c.500W, d. 10KW, ans: d, 49. A current of 2A flows for 10 h through, a100Ωresistor. The energy consumed by the, resistor is, , 50. Amount of heart energy required to raise, the temperature of 10kg of water through, 100oC is (Sw of water as 4200J/kgK), a. 4.2kJ, b.4.2MJ, c. 42kJ, d. 420J, ans:b, 51. The opposition to the flow of leakage, current is called as, a. resistance, b. leakage coefficient, c. insulation resistance, d. all above, ans:c, 52. The insulation resistance is generally, measured in.., a. ohms, b. Mega ohms, c. milli ohms, d. none of above, ans:b, 53. The insulation resistance of a cable is, a. directly proportional to length of cable, b. inversely proportional to length of cable, c. remains same with change in length, d. none of above, ans:b, 54. Which is the expression for insulation, resistance of a single core cable, a. R=ρ l/a, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 5

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Basic Electrical Engineering, b. Ri=, c. Ri=, , ρ, π, ρ, π, , Multiple Choice Questions, d. all of above, ans: b, , 𝑙𝑛(R2/R1), (R2/R1), , d. none of above, ans:b, 55. As the thickness of insulation layer of a, cable increases, it’s insulation resistance will, a. increase, b. decrease, c. remain same, d. none of above, ans: a, 56. As the Temperature of surrounding, increases the insulation resistance will, a. increase, b. remain same, c. decrease, d. none of above, ans: c, 57. Which is a good conductor of electricity?, a. normal tap water, b. pure water, c. glass, d. plastic, ans: b, 58. As moisture content in the air increases,, then the insulation resistance will, a. decrease, b. remain same, c. increase, d. none of above, ans: a, 59. When the Humidity in the surrounding, increases, the leakage current in the cable will, a. remain same, b. increase, c. decrease, , 60. Factors affecting the insulation resistance of, a cable are, a. length, b. thickness, c. resistivity of insulating material, d. all above, ans:d, 61. If length of cable is doubled, then its, insulation resistance will, a. reduce by 25%, b. reduce by 50%, c. increase by 50%, d. reduce by 55%, ans:b, 62 .If two cables with their insulation, resistances Ri1 and Ri2 are joined in series, then, their equivalent resistance will be, a. Ri1 + Ri2, b. Ri1 - Ri2, c. Ri1 / Ri2, d. (Ri1.Ri2) / (Ri1 + Ri2), ans:d, 64. If the thickness of insulation layer of cable is, doubled, then its insulation resistance will, a. reduce by 25%, b. increase by 50%, c. increase by 58.5%, d. reduce by 55%, ans:c, 65. If two cables with their insulation, resistances Ri1 and Ri2 with conductor, resistances R1and R2 respectively are joined in, parallel, then their conductor equivalent, resistance will be, a. R1 + R2, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 6

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Basic Electrical Engineering, b. Ri1 - Ri2, c. Ri1 / Ri2, d. (R1 R2) / (R1 + R2), ans: d, , Multiple Choice Questions, 71. According to Ohm’s law current in, conducting material is inversely proportional, to…., a. Voltage across it., b. Both Voltage and Resistance., c. Resistance of material., d. None of above., ans:c, , 66. What is current?, a. Flow of electrons., b. Flow of protons, c. Flow of Neutrons., d. None of above., ans: a, 67. What is Resistance?, a. to assist the flow of current., b. opposition the flow of current., c. opposition the flow of voltage., d. to assist the flow of voltage., ans:a, , 72. What are the factors on which resistance of, material depends?, a. Length and Cross-section area of material., b. Temperature of material., c. Specific resistivity of material., d. All of above., ans:d, , 68. Unit of resistance is…, a. Volts., b. Amperes., c. Ohm., d. Faraday., ans:c, , 73. Resistance of material will increase with, increase of?, a. Cross-section area of material., b. Length of material., c. Both Length and Cross-section area of, material., d. None of above., ans:b, , 69. Resistance of material will decrease with, increase of….., a. Length of material., b. Both Length and Cross-section area of, material., c. Cross-section area of material., d. None of above., ans:c, , 74. What will be the effect on the resistance of, conducting material if the temperature, increases?, a. No effect on resistance., b. Resistance will increase., c. Resistance will decrease., d. Resistance will remain same., ans:b, , 70. According to Ohm’s law current in the, conducting material is directly proportional to…, a. Resistance of material., b. Voltage across., c. Both Voltage and Resistance., d. None of above., ans:b, , 75. What will be the effect on the resistance of, conducting material if the temperature, decreases?, a. Resistance will remain same., b. No effect on resistance., c. Resistance will increase., d. Resistance will decrease., , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 7

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Basic Electrical Engineering, ans:d, 76. What will be the effect on the resistance of, insulating material if the temperature, increases?, a. No effect on resistance., b. Resistance will increase., c. Resistance will remain same., d. Resistance will decrease., ans:d, 77. What will be the effect on the resistance of, insulating material if the temperature, decreases?, a. Resistance will remain same., b. No effect on resistance., c. Resistance will increase., d. Resistance will decrease., ans:c, 78. What will be the resistance of semiconductor at low temperature?, a. Resistance will be high., b. Resistance will be low., c. No effect on resistance, d. None of above., ans:a, 79. What will be the resistance of semiconductor at high temperature?, a. Resistance will be high, b. No effect on resistance., c. Resistance will be low., d. None of above., ans:c, 80. At low temperature semi-conductor will, behave as?, a. Insulator., b. Conductor., c. Semi-conductor., d. None of above., ans:a, , Multiple Choice Questions, 81. At high temperature semi-conductor will, behave as?, a. Insulator., b. Conductor., c. Semi-conductor., d. None of above., ans:b, 82. The length of a conductor or a wire is, doubled and its cross section is also doubled, then the resistance will., a. Increases four times., b. Remains unchanged., c. Decreases four times., d. Change at random., ans:b, 83. The variation of resistance with, temperature is governed by a property called., a. Resistance access coefficient (RAC)., b. Resistance nature coefficient (RNC)., c. Resistance temperature coefficient (RTC)., d. None of above., ans:c, 84. Temperature co-efficient of resistance at, 00C is defined as the change in resistance per, ohm original resistance per 0C change in, temperature., a. True., b. False., ans:a, 85. Unit of Temperature, resistance is., a. /Ώ/0C., b. /0C., c. 0C., d. Ώ/0C., ans:b, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , co-efficient, , of, , Page 8

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Basic Electrical Engineering, 86. Temperature co-efficient of resistance α0 is, given by., a. 𝛼 =, b. 𝛼 =, c. 𝛼 =, d. 𝛼 =, , ., ., ., ., , ans:a, 87. At 00C a specimen of copper have a, resistance of 4mΏ and its temperature coefficient of resistance equal to 1/234.5 per 00C., Find the value of its temperature co-efficient at, 700C., a. 0.003248/0C., b. 0.003428/0C., c. 0.003284/0C., d. 0.003434/0C., ans:, 88. At 00C a specimen of copper have a, resistance of 4mΏ and its temperature coefficient of resistance equal to 1/234.5 per 00C., Find the value of resistance at 700C., a. 4.5mΩ., b. 3.5mΩ., c. 5.19mΩ., d. 5.5mΩ., ans:c, 90. An aluminum conductor has resistance of, 10Ω AT 200C and the RTC of 0.0039 per 0C at, 200C .Find the RTC at 00C., a. 0.000124/0C., b. 0.00423/0C., c.0.00324/0C., d. 0.0000423/0C., ans:b, 91. Find the resistance of filament of 60 watt in, a 230 V supply lamp at its working temperature., , Multiple Choice Questions, a. 990 Ω., b. 881.667 Ω., c. 981.667 Ω., d. 1000 Ω., ans:b, 92. A single core cable has 1.5cm diameter, conductor and thickness of insulation is 2.2 cm., The resistivity of insulating material is 9.2×1012, Ώ-m. Determine the insulation resistance per, km length of cable., a. 2×1012 Ώ., b. 2.9×1013 Ώ., c. 2×109 Ώ., d. 9.2×1012 Ώ., ans:c, 93. A single core cable has 1.5cm diameter, conductor and thickness of insulation is 2.2 cm., The resistivity of insulating material is 9.2×1012, Ώ-m. Determine the insulation resistance per, km length of cable. If the working voltage of, conductor is 1100V, what is the leakage current, per km of cable?, a. 0.55×10-6A., b. 1.55×10-6A., c. 0.55×10-12A., d. 0.55×106A., ans:a, 94. The armature winding of a D.C. machine, when connected to D.C. supply of 240 V was, drawing 1.6 A at 250C and 1.25 A when heated., Evaluate temperature of armature winding if α, of its material at 250C is 0.0039/0C., a. 1000C., b. 1100C., c. 96.790C., d. 98.790C., ans:c, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 9

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Basic Electrical Engineering, 95. If the length of a wire of resistance R is, uniformly stretched to n times its original value,, its new resistance is, a.nR, b. R/n, c. n2R, d.r/n2, ans:c, 96. Two wires A and B of same material and, length L and 2L have radius r and 2r, respectively. The ratio of their specific, resistance will be, a.1:1, b.1:2, c.1:4, d.1:8, ans:a, 97. Two wires A and B of same material and, length L and 2L have radius r and 2r, respectively. The ratio of their resistances will, be, a.1:1, b.2:1, c.4: 1, d.1:8, ans:b, 99. A length of wire having resistance of 1 ohm, is cut into four equal parts and these four parts, are bundled together side-by-side to form a, wire. The new resistance will be, a.1/4 ohm, b.1/16 ohm, c.4 ohm, d.16 ohm, ans:b, 100. The hot resistance of filament of a bulb is, higher than the cold resistance because the, temperature coefficient of filament is, , Multiple Choice Questions, a. negative, b. infite, c. zero, d. positive, ans: d, 101. Insulation resistance of the insulating, material should be, a. high, b. low, c. zero, d. none of these, ans:a, 102. The flow of current in solids is due to, a. electrons, b. electrons and ions, c. atoms, d. nucleus, ans: a, 103. The resistance of human body is around, a. 5 ohms, b. 25 ohms, c. 250 ohms, d. 1000 ohms, ans:d, 104. One commercial unit of energy equals, a. 500 watt seconds, b. one watt hour, c. one kilowatt hour, d. ten kilowatt hour, ans:c, 105. One coulomb charge equals the charge on, a. 6.24x1012 electrons, b. 6.24x1014 electrons, c. 6.24x1016 electrons, d. 6.24x1018 electrons, ans:d, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 10

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Basic Electrical Engineering, 106. Electric pressure is also called, a. resistance, b. power, c. voltage, d. energy, ans:c, 107. With rise in temperature resistance of pure, metals, a. increases, b. decreases, c. first increases then decreases, d. remains constant, ans:a, 108. With rise in temperature resistance of, semiconductors, a. increases, b. decreases, c. first increases then decreases, d. remains constant, ans:b, 109. The resistance of copper wire 200 m long is, 21 ohms. If its thickness is 0.44 mm, its specific, resistance is around, a. 1.2x10-8Ω-m, b. 1.4x10-8Ω-m, c. 1.6x10-8Ω-m, d. 1.8x10-8Ω-m, ans:c, 110. Which of the following material has nearly, zero temperature coefficient of resistance, a. manganin, b. porcelain, c. carbon, d. copper, ans:a, 111. Which of the following material has a, negative temperature coefficient of resistance, , Multiple Choice Questions, a. copper, b. aluminum, c. carbon, d. brass, ans:c, 112. Ohm’s law is not applicable to, a. vaccum tubes, b. carbon resistor, c. high voltage circuits, d. circuits at low current densities, ans:a, 113. Which one of the following does not have, negative temperature coefficient, a. aluminum, b. paper, c. rubber, d. mica, ans:a, 114. An electrical effort required to drift the, free electrons in one particular direction, in a, conductor is called, a.MMF, b.EMF, c. current, d. all above, ans:b, 115. An _______ effort required to drift the free, electrons in one particular direction, in a, conductor is called EMF, a. chemical, b. mechanical, c. electrical, d. thermal, ans:c, 116. I = ___ /t amp, a. R, b. L, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 11

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Basic Electrical Engineering, c. Q, d. t, ans:c, 117. The ability of a charged particle to do work, is called, a. potential difference, b. electric potential, c. magnitude, d. magnetism, ans:b, 118. The unit of electric potential is ___, a.amp, b. coulomb, c. volt, d. tesla, ans:c, 119. 1 calorie = ___, a.4.186 joules, b.0.24 joules, c.41.86 joules, d. none of the above, ans:a, 120. Unit of resistivity is ____, a. Ω, b. Ω-m, c. Ω/m, d. all above, ans:b, 121. Unit of conductance is ___, a. ohms, b. siemens, c. newtons, d. none of above, ans:b, 122. The material having highest value of ____, is best conductor, , Multiple Choice Questions, a. resistivity, b. conductivity, c. permittivity, d. all above, ans:b, 123. The material having poorest value of ____, is best insulator., a. resistivity, b. conductivity, c. permittivity, d. all above, ans:b, 124. The resistance of copper wire 25 m long is, found to be 50 Ω. If its diameter is 1mm, then, resistivity of copper is ___, a.1.57 µΩ-m, b.1.57 Ω-m, c.15.7 Ω-m, d. none of the above, ans:a, 125. Factors which affect the resistance _____, a. length of the material, b. cross sectional area, c. temperature, d. all above, ans:d, 126. Effect of temperature on resistance, depends on ____ of material, a. size, b. shape, c. nature, d. length, ans:c, 127. Resistance of carbon _____ as the, temperature increases, a. increases, b. remains same, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 12

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Basic Electrical Engineering, , Multiple Choice Questions, , c. decreases, d. none of above, ans:c, , d. all above, ans:c, , 128. Semiconductors have _____ temperature, coefficient, a. positive, b.negative, c.zero, d.all above, ans:b, 129. Resistance temperature coefficient is, denoted by ____, a. α, b. β, c. θ, d. Φ, ans:a, O, , 130. The RTC at t C is ratio of _____, a. change in conductance per degree Celsius to, the resistance at t0 C, b. change in resistance per degree Celsius to the, resistance at t0 C, c. change in initial resistance per degree Celsius, to the resistance at t0 C, d. all above, ans:b, 131. Unit of RTC is ____, a. OC, b. /OC, c. Ω/ OC, d. all above, ans:b, 132. Insulation resistance is, opposition to the flow of ____, a. current, b. voltage, c. leakage current, , defined, , as, , 133. Insulation resistance Ri = V/Il, in this V is, ____, a. voltage between conductor and earth, b. voltage between insulation and earth, c. voltage between conductor and insulator, d. all above, ans:a, 134. Insulation resistance Ri = V/Il, in this Il is, ____, a. current, b. voltage, c. leakage current, d. line current, ans:c, 135., Insulation, resistance, proportional to its length, a. directly, b. inversely, c. not, d. none of above, ans:b, 136. Insulation resistance, proportional to its ______, a. length, b. area, c. diameter, d. cross sectional area, ans: a, , is, , is, , ______, , inversely, , 137. Which of the following substance, the, resistance decreases with the increase of, temperature?, a. carbon, b. constantan, c. copper, d. silver, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , Page 13

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Basic Electrical Engineering, ans:a, 138. At 300K the temperature coefficient of, resistance of a wire is 0.00125 /OC and its, resistance is one ohm. The resistance of wire, will be 2 ohm at, a. 1154 K, b. 1100 K, c. 1400 K, d. 1127 K, ans: b, 139. The conventional electric current is due to, the flow of, a. positive charges only, b. negative charges only, c. neutral particles only, d. both positive and negative charges., ans:b, 140. Insulators have _______ temperature, coefficient of resistance, a. positive, b. negative, c. zero, d. none of the above, ans:b, 141. Two underground cables A and B, each has, a conductor resistance of 0.6 Ω and 0.8 Ω resp., each has insulation resistance of 600 MΩ and, 400 MΩ resp. if cables are connected in series,, its conductor resistance is ___, a.1.2 MΩ, b.1.2 Ω, c.1.4 Ω, d. 1.6 Ω, ans:c, 142.Two underground cables A and B, each has, a conductor resistance of 0.6 Ω and 0.8 Ω resp., each has insulation resistance of 600 MΩ and, , Multiple Choice Questions, 400 MΩ resp. if cables are connected in series,, its insulation resistance is ___, a.120 MΩ, b.240 Ω, c.240 MΩ, d. 160 Ω, ans:c, 143.Two underground cables A and B, each has, a conductor resistance of 0.6 Ω and 0.8 Ω resp., each has insulation resistance of 600 MΩ and, 400 MΩ resp. if cables are connected in parallel,, its insulation resistance is ___, a.1200 MΩ, b.2400 Ω, c.1000 MΩ, d. 1600 Ω, ans:c, 144. Two underground cables A and B, each has, a conductor resistance of 0.6 Ω and 0.8 Ω resp., each has insulation resistance of 600 MΩ and, 400 MΩ resp. if cables are connected in parallel,, its conductor resistance is ___, a.0.3428Ω, b.0.240 Ω, c.0.240 MΩ, d. 0.160 Ω, ans:a, 145. Match the pair, 1. Resistance, 2. Insulation resistance, 3. RTC, 4. Conductance, a. 1a,2-b,3-c,4-d, b.1-c,2-d,3-a,4-b, c.1-d,2-c,3-b,4-a, d.all above, ans:b, , Sinhgad Institute of Technology Lonavala, , Follow @PuneEngineers | Telegram, , a. /0C, b.siemens, c.ohm, d.MΩ, , Page 14

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UNIT IVA, B. direction only, C. both magnitude and direction, D. neither magnitude nor direction, Ans. C, , Que. The distance occupied by one, complete cycle of the wave is called, its________, A. time period, B. wavelength, C. velocity, D. frequency, Ans. A, , Que. An alternating current of 50 Hz, frequency and 100 A maximum value is given, by______, A. 𝑖 = 200 𝑠𝑖𝑛628𝑡, B. 𝑖 = 100 𝑠𝑖𝑛314𝑡, C. 𝑖 = 100√2 𝑠𝑖𝑛314𝑡, D. 𝑖 = 100√2𝑠𝑖𝑛157𝑡, Ans. B, , Que. The rms value of a sine wave of peak, value Imis given by_______, A. Im/√2, B. Im, C. Im/2, D. Im/π, Ans. A, , Que. An alternating current is given by the, 𝜋, expression 𝑖 = 200 sin(314𝑡 + 3 ) amperes., The maximum value and frequency of the, current are_________, A. 200 A, 50 Hz, B. 100√2, 50 Hz, C. 200 A, 100 Hz, D. 200 A, 25 Hz, Ans. A, , Que. The average value of a sine wave of, maximum value I m over one cycle is_______, A. Im/π, B. 2Im/π, C. zero, D. Im/2, Ans. C, , Que. When two quantities are in quadrature,, the phase angle between them will, be________, A. 45°, B. 90°, C. 135°, D. 60°, Ans. B, , Que. The time period of a sinusoidal, waveform, with, 200, Hz, frequency, is________second., A. 0.05, B. 0.005, C. 0.0005, D. 0.5, Ans. B, , Que. The ac system is preferred to dc system, because_______, A. ac voltages can be easily changed in, magnitude, B. dc motors do not have fine speed control, C. high voltage ac transmission is less efficient, D. dc voltage can not be used for domestic, appliances, Ans. A, , Que. The form factor of a sine wave is_____, A. 1.01, B. 1.11, C. 1.21, D. none of the above, Ans. B, Que. A current is said to be alternating when it, changes in_______, A. magnitude only, , Que. In ac system, we generate sine waveform, because_______, A. it can be easily drawn, 54, , Follow @PuneEngineers | Telegram

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B. it produces least disturbance in electrical, circuits, C. it is nature’s standard, D. other waves can not be produced easily, Ans. B, , Que. An alternating voltage is given by 𝑣 =, 30 𝑠𝑖𝑛314𝑡 .The time taken by the voltage to, reach 30 V for the first time is_____, A. 0.02 second, B. 0.1 second, C. 0.03 second, D. 0.005 second, Ans. D, , Que. __________will work only on dc supply., A. electric lamp, B. refrigerator, C. electroplating, D. heater, Ans. C, , Que. A sinusoidal current has a magnitude of 3, A at 120°. Its maximum value will be_____, A. √3 A, √3, , Que. _________will produce ac voltage., A. friction, B. photoelectric effect, C. thermal energy, D. crystal, Ans. D, , B. A, 2, C. 2√3 A, D. 6 A, Ans. C, Que. We have assigned a frequency of 50Hz to, power system because it_______, A. can be easily obtained, B. gives best result when used for operating, both lights and machinery, C. leads to easy calculations, D. none of the above, Ans. B, , Que. A coil is rotating in the uniform field of, an 8-pole generator. In one revolution of the, coil, the number of cycles generated by the, voltage is________, A. one, B. two, C. four, D. eight, Ans. C, , Que. An alternating voltage is given by 𝑣 =, 100 𝑠𝑖𝑛314𝑡 volts. Its average value will, be________, A. 70.7 V, B. 50 V, C. 63.7 V, D. 100 V, Ans. C, , Que. An alternating voltage is given by 𝑣 =, 20 sin 157𝑡. The frequency of the alternating, voltage is_____, A. 50 Hz, B. 25 Hz, C. 100 Hz, D. 75 Hz, Ans. B, , Que. An alternating current whose average, value is 1 A will produce_________1 A dc, under similar conditions., A. less heat than, B. more heat than, C. the same heat as, D. none of the above, Ans. B, , Que. A sine wave has a maximum value of 20, V. Its value at 135° is______, A. 10 V, B. 14.14 V, C. 15 V, D. 5 V, Ans. B, 55, , Follow @PuneEngineers | Telegram

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Que. A sinusoidal alternating current has a, maximum value of I m. Its average value will, be_______, 𝐼𝑚, A. 𝜋, , Que. The direction of current in an ac circuit, is___________, A. always in one direction, B. varying from time to time, C. unpredictable, D. from positive to negative, Ans. B, , 𝐼𝑚, , B. 2𝜋, , 𝐼𝑚, , C. 2 𝜋, D. none of the above, Ans. C, , Que. Consider the sinusoidal waves:, 𝐴sin(𝜔𝑡 + 30°) and 𝐵sin(𝜔𝑡 − 60°). The, phase angle relationship between the two, waves________, A. B-wave lags A-wave by 90°, B. B-wave lags A-wave by 60°, C. B-wave lags A-wave by 30°, D. B-wave and A-wave are in phase, Ans. A, , Que. The area of a sinusoidal wave over a, half-cycle is________, A. 𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 2, B. 2 × 𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒, C. 𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 𝜋, D. 𝑚𝑎𝑥. 𝑣𝑎𝑙𝑢𝑒 ÷ 2𝜋, Ans. B, Que. An alternating voltage is given by 𝑣 =, 200 𝑠𝑖𝑛314𝑡. Its rms value will be_____, A. 100 V, B. 282.8 V, C. 141.4 V, D. 121.4 V, Ans. C, , Que. A sinusoidal voltage is expressed as 𝑣 =, 𝜋, 20 sin(314.16𝑡 + 3 ) V. Its frequency and, phase angle respectively are____________, A. 314.16 Hz, 60°, B. 60Hz, 60°, C. 50 Hz, 60°, D. 50 Hz, -60°, Ans. C, , Que. A sinusoidal voltage is represented as, 𝜋, 𝑣 = 141.4 sin(314.18𝑡 − 2 ). Its rms value of, voltage, frequency and phase angle are, respectively_______, A. 141.42 V, 314.16 Hz, 90°, B. 100 V, 100 Hz, -90°, C. 87.92 V, 56 Hz, 90°, D. 100 V,50 Hz, -90°, Ans. D, , Que. A sinusoidal voltageV1 leads another, sinusoidal, voltage, V2, by, 180°., Then__________, A. voltageV2 leads voltage V1by 180°, B. both voltage have their zero values at the, same time, C. both voltages have their peak values at the, same time, D. all of the above, Ans. D, , Que. When two sinusoidal waves are 90° out, of phase, then__________, A. both have their peak values at the same, instant, B. both have their minimum values at the same, instant, C. one has its peak value; while the other has, zero value, D. none of these, Ans. C, , Que. The rms value of an ac sinusoidal current, is 10 A. Its peak value is_________, A. 7.07 A, B. 14.14 A, C. 10 A, D. 28.28 A, Ans. B, 56, , Follow @PuneEngineers | Telegram

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C. -1, 1, D. 2, Ans. A, , Que. If A=10∠45° and B=5∠15°, then the, value of A/B will be_________, A. 50∠60°, B. 2∠60°, C. 2∠-30°, D. 2∠30°, Ans. D, , Que. An alternating current is given by 𝑖 =, 𝐼𝑚 𝑠𝑖𝑛𝜃. The average value of squared wave, of this current over a complete cycle, is________, A. I2m/2, B. Im/π, C. 2Im/π, D. 2Im, Ans. A, , Que. When a phasor is multiplied by –j, it gets, rotated, through_______in, the, counterclockwise direction., A. 90°, B. 180°, C. 270°, D. none of the above, Ans. C, , Que. The form factor of a sinusoidal wave, is______, A. 1.414, B. 1.11, C. 2, D. 1.5, Ans. B, , Que. The rms value of sinusoidally varying, current is_________that of its average value., A. more than, B. less than, C. same as, D. none of the above, Ans. A, , Que. The filament of a vacuum tube requires, 0.4A dc to heat it. The rms value of ac, required is______, A. 0.4 × √2 A, B. 0.4 ÷ 2 A, C. 0.8 ÷ √2 A, D. 0.4 A, Ans. D, , Que. Alternating voltages and currents are, expressed in rms values because______, A. they can be easily determined, B. calculations become very simple, C. they give comparison with dc, D. none of the above, Ans. C, , Que. A100 V peak ac is as effective, as_____dc, A. 100 V, B. 50 V, C. 70.7 V, D. none of the above, Ans. C, , Que. The average value of sin2θ over a, complete cycle is_________, A. +1, B. -1, 1, C. 2, D. zero, Ans. C, , Que. The form factor of a ________wave is 1., A. sinusoidal, B. square, C. triangular, D. sawtooth, Ans. B, , Que. The average value of sinθ over a, complete cycle is_________, A. zero, B. +1, 57, , Follow @PuneEngineers | Telegram

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Que. Out of the following _________wave is, the peakiest., A. sinusoidal, B. square, C. rectangualr, D. triangular, Ans. D, , Que. A heater is rated as 230V, 10KW, AC., The value of 230V refers to___________, A. average voltage, B. rms voltage, C. peak voltage, D. none of the above, Ans. B, , Que. The peak factor of a sine waveform, is_______, A. 1.11, B. 1.414, C. 2, D. 1.5, Ans. B, , Que. The peak value of a sine wave is 200V., Its average value is_______, A. 127.4V, B. 141.4V, C. 282.8V, D. 200V, Ans. A, , Que. When a 15V square wave is connected, across a 50V ac voltmeter, it will read______, A. 15V, B. 15 × √2 V, C. 15/√2 V, D. none of the above, Ans. A, , Que. The rms value of a sine wave is 100A., Its peak value is _______, A. 70.7A, B. 141.4A, C. 150A, D. 282.8A, Ans. B, , Que. The period of a wave is____________, A. the same as frequency, B. time required to complete one cycle, C. expressed in amperes, D. none of the above, Ans. B, , Que. The voltage of domestic supply is 220V., This figure represents________, A. mean value, B. rms value, C. peak value, D. average value, Ans. B, , Que. The form factor is the ratio of _________, A. peak value to rms value, B. rms value to average value, C. average value to rms value, D. none of the above, Ans. B, , Que. The rms value and mean value is the, same in the case of_______, A. traingular wave, B. sine wave, C. square wave, D. half wave rectified sine wave, Ans. C, , Que. The period of a sine wave is 1/50, seconds. Its frequency is_______, A. 20 Hz, B. 30 Hz, C. 40 Hz, D. 50 HZ, Ans. D, , Que. For the same peak value which of the, following wave will have the highest rms, value?, A. square wave, B. half wave rectified sine wave, C. triangular wave, 58, , Follow @PuneEngineers | Telegram

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A. 0.05 S, B. 0.005 S, C. 0.0005 S, D. 0.5 S, Ans. B, , D. sine wave, Ans. A, Que. For the same peak value which of the, following wave will have the least mean, value?, A. half wave rectified sine wave, B. triangular wave, C. sine wave, D. square wave, Ans. A, , Que. An ac voltage of 50 Hz has a maximum, value of 50 V. Its value after 1/600 second, after the instant the current is zero will, be_________, A. 5V, B. 12.5V, C. 25V, D. 43.8V, Ans. C, , Que. For a sine wave with peak value Imax, the, rms value is_______, A. 0.5Imax, B. 0.707Imax, C. 0.9Imax, D. 1.414Imax, Ans. B, Que. Form factor is the ratio of_________, A. average value/rms value, B. average value/peak value, C. rms value/average value, D. rms value/peak value, Ans. C, , Que. For 200V rms value triangular wave, the, peak voltage will be______, A. 200V, B. 222V, C. 282V, D. 346V, Ans. D, , Que. For a sine wave with peak value Emax, the, average value is______, A. 0.636Emax, B. 0.707Emax, C. 0.434Emax, D. 1.414Emax, Ans. A, , Que. The rms value of a half-wave rectified, current is 100 A. Its value for full-wave, rectification would be_________amperes., A. 141.4, B. 200, C. 200/π, D. 40/π, Ans. A, , Que. The current in a circuit is given by: 𝑖 =, 100 sin 314𝑡 amperes. The maximum value, and frequency of current are_________, A. 50√2 A, 100 Hz, B. 100√2 A, 100 Hz, C. 100 A, 50 Hz, D. 70.7 A, 50 Hz, Ans. C, , Que. The rms value of a sinusoidal ac current, is equal to its value at an angle of, ______degrees., A. 90, B. 60, C. 45, D. 30, Ans. C, , Que. For a frequency of 200 Hz, the time, period will be_________, 59, , Follow @PuneEngineers | Telegram

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C. 60 Hz, D. 50 Hz, Ans. D, , Que. The rms value of alternating current is, given by steady dc current which when, flowing through a given circuit for a given, time produces________, A. the more heat than produced by ac when, flowing through the same circuit, B. the same heat as produced by ac when, flowing through the same circuit, C. the less heat than produced by ac flowing, through the same circuit, D. none of the above, Ans. B, , Que. The rms value of half wave rectified sine, wave is 200V. The rms value of full wave, rectified ac will be__________, A. 282.8V, B. 141.4V, C. 111V, D. 100V, Ans. A, Que. The negative maximum of a cosine wave, occurs at________, A. 30°, B. 45°, C. 90°, D. 180°, Ans. D, , Que. The square waveform of current has, following relation between rms value and, average value:, A. rms value is equal to average value, B. rms value of current is greater than average, value, C. rms value of current is less than average, value, D. none of the above, Ans. A, , Que. The rms value of pure cosine function, is_________, A. 0.5 of peak value, B. 0.707 of peak value, C. same as peak value, D. zero, Ans. B, , Que. If a sinusoidal wave has frequency of 50, Hz with 30A rms current, which of the, following equation represents the wave?, A. 42.42 sin 314𝑡, B. 60 𝑠𝑖𝑛25𝑡, C. 30 sin 50𝑡, D. 84.84 𝑠𝑖𝑛25𝑡, Ans. A, , Que. An alternating voltage is given in volts, by expression 𝑣 = 326 𝑠𝑖𝑛314𝑡. Its rms value, and frequency are____, A. 230V,50 Hz, B. 230V,100 Hz, C. 326V,50 Hz, D. 326V,100 Hz, Ans. A, , Que. Which of the following waves has the, highest value of peak factor?, A. square wave, B. sine wave, C. half wave rectified sine wave, D. triangular wave, Ans. C, , Que. According to which of the alternating, current values in the cross sectional area of a, conductor with regard to the heating effect is, selected?, A. peak value, B. half peak value, C. average value, , Que. The frequency of domestic power supply, in India is_____, A. 200 Hz, B. 100 Hz, 60, , Follow @PuneEngineers | Telegram

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D. rms value, Ans. D, , C. unsymmetrical part of the waveform, D. first two cycles, Ans. A, , Que. The frequency of an alternating current, is________, A. the speed with which the alternator runs, B. the number of cycles generated in one, minute, C. the number of waves passing through a, point in one second, D. the number of electrons passing through a, point in one second, Ans. C, , Que. A constant current of 2.8A exists in a, resistor. The rms value of current is______, A. 2.8 A, B. about 2 A, C. 1.4 A, D. undefined, Ans. A, Que. An alternating current is represented as, 𝜋, 𝑖 = 70.7 sin(520𝑡 + 6 ). The frequency and, rms value of the current are_________, A. 82.76 Hz, 50 A, B. 41.38 Hz, 25 A, C. 41.38 Hz, 50 A, D. 82.76 Hz, 25 A, Ans. A, , Que. The equation of 50 Hz current sine wave, having rms value of 60 A is______, A. 60 sin 25𝑡, B. 60 sin 50𝑡, C. 84.84 𝑠𝑖𝑛314𝑡, D. 42.42 𝑠𝑖𝑛314𝑡., Ans. C, , Que. The time period or periodic time T of an, alternating quantity is the time taken in, seconds to complete_____________, A. one cycle, B. alternation, C. none of the above, D. Half cycle, Ans. A, , Que. The direction of current in an ac, circuit________, A. is from positive to negative, B. is always in one direction, C. varies from instant to instant, D. can not be determined, Ans. C, Que. The angular frequency of an alternating, quantity is a mathematical quantity obtained, by multiplying the frequency “f” of the, alternating quantity by a factor_________, 𝜋, A. 2, B. π, C. 2π, D. 4π, Ans. C, , Que. The time period of an alternating quantity, is 0.02 second.Its frequency will be________, A. 25 Hz, B. 50 Hz, C. 100 Hz, D. 0.02 Hz, Ans. B, Que. The size (cross-sectional area) of a, conductor, with regard to the heating effect, is, determined on the basis of ……….. value of, current to be carried by it, A. average value, B. peak value, C. rms value, D. peak to peak value, , Que. The average value of an unsymmetrical, alternating quantity is calculated over, the_________, A. whole cycle, B. half cycle, 61, , Follow @PuneEngineers | Telegram

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B. time, C. time period, D. all above, Ans. C, , Ans. C, Que. The form factor for dc supply voltage is, always, A. zero, B. unity, C. infinity, D. any value between 0 and 1, Ans. B, , Que., Que. The ________ varying alternating, quantity can be represented as phasor., A. circular, B. sinusoidally, C. rectangular, D. triagular, Ans. B, , In the above figure, the phase quantity at A is, _______, A. T, B. T/2, C. T/3, D. T/4, Ans. D, , Que. The phasors are assumed to be rotated in, _________ direction., A. clockwise, B. anticlockwise, C. circular, D. all above, Ans. B, , Que., , Que. In practice, alternating quantities are, represented by their _______ values, A. rms, B. average, C. rectangular, D. polar, Ans. A, , In the above figure, the phase quantity at B is, _______, A. T, B. T/2, C. 3T/4, D. T/4, Ans. C, , Que. Alternating quantities of ____, frequencies can be represented on same phasor, diagram., A. Same, B. Different, C. multiple, D. all above, Ans. A, , Que. When phase of an alternating quantity is, positive it means that quantity has some, _______ instantaneous value at t=0, A. zero, B. positive, C. negative, D. none of the above, , Que. The phase of alternating quantity at any, particular instant is the fraction of ______, A. phase, 62, , Follow @PuneEngineers | Telegram

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Ans. B, Que. When phase difference between the two, alternating quantities is _______, the two, quantities are said to be in phase., A. one, B. unity, C. zero, D. π/2, Ans. C, , Que. When phase of an alternating quantity is, negative it means that quantity has some, _______ instantaneous value at t=0, A. zero, B. positive, C. negative, D. none of the above, Ans. C, , Que. If v = Vm Sin ωtand i = Im Sin (ωt-Φ),, the ‘v’ is said to _______ ‘i’ by angle Φ, A. in phase, B. lagging, C. leading, D. all above, Ans. C, , Que. The difference between the _____ of two, alternating quantities is called the phase, difference., A. time, B. phase angle, C. Lengths, D. both a and b, Ans. B, , Que. If v = Vm Sin ωt and i = Im Sin (ωt+Φ),, the ‘i’ is said to _______ ‘v’ by angle Φ, A. in phase, B. lagging, C. leading, D. all above, Ans. C, , Que. The difference between the phase of two, alternating quantities is called the________., A. phase difference, B. sinedifference, C. length difference, D. none of the above, Ans. A, , Que. If v = Vm Sin ωtand i = Im Sin (ωt+Φ),, the ‘v’ is said to _______ ‘i’ by angle Φ, A. in phase, B. lag, C. lead, D. all above, Ans. B, , Que. When phase difference between the two, alternating quantities is zero, the two, quantities are said to be in _____, A. tandom, B. length, C. phase, D. time, Ans. C, , Que. If v = Vm Sin ωtand i = Im Sin ωt, the ‘i’, is said to _______ ‘v’ by angle Φ, A. in phase, B. lag, C. lead, D. all above, Ans. A, , Que. When ____________ between the two, alternating quantities is zero, the two, quantities are said to be in phase., A. time difference, B. length difference, C. phase difference, D. none of the above, Ans. C, , Que. With respect to reference, plus sign of, angle indicates _______, A. leading, 63, , Follow @PuneEngineers | Telegram

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B. lagging, C. inphase, D. none of the above, Ans. A, , B. frequency, C. sign, D. shape, Ans. B, , Que. With respect to reference, minus sign of, angle indicates _______, A. leading, B. lagging, C. inphase, D. none of the above, Ans. B, , Que. The lagging and leading word is relative, to the ______, A. base, B. range, C. reference, D. angle, Ans. C, , Que. With respect to reference, _____ sign of, angle indicates lead, A. division, B. plus, C. minus, D. dot, Ans. B, , Que. In purely _____ circuit, the current, flowing and voltage applied are in phase with, each other., A. resistive, B. inductive, C. capacitive, D. none of the above, Ans. A, , Que. With respect to reference, _____ sign of, angle indicates lag., A. division, B. plus, C. minus, D. dot, Ans. C, , Que. In purely resistive circuit, the current and, voltage applied are in ______ with each other., A. opposition, B. phase, C. direction, D. line, Ans. B, , Que. The diagram in which different, sinusoidal alternating quantities of the same, frequency, are represented by individual, phasors indicating exact phase relationship is, called ________, A. graph, B. still diagram, C. phasor diagram, D. picture, Ans. C, , Que. In purely _______ circuit, current lags, voltage by 90 degrees., A. resistive, B. inductive, C. capacitive, D. none of the above, Ans. B, Que. In purely Inductive circuit, current _____, voltage by 90 degrees., A. leads, B. lags, C. in phase, D. all above, Ans. B, , Que. The diagram in which different, sinusoidal alternating quantities of the same, _____, are represented by individual phasors, indicating exact phase relationship is called, phasor diagram., A. time, 64, , Follow @PuneEngineers | Telegram

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Que. In purely Inductive circuit, current lags, voltage by _______ degrees., A. 30, B. 60, C. 90, D. 120, Ans. C, , Que. Inductive reactance is measured in, ______, A. Farad, B. Henry, C. Ohm, D. Joule, Ans. C, , Que. The inductance offers _____ reactance to, DC, A. high, B. low, C. zero, D. none of the above, Ans. C, , Que. Inductive reactance depends on ______, of applied voltage, A. phase, B. sign, C. frequency, D. speed, Ans. C, , Que. The _________ offers zero reactance to, DC, A. resistance, B. inductance, C. permeance, D. none of the above, Ans. B, , Que. Inductive reactance, frequency., A. inversely proportional to, B. directly proportional to, C. indepedent of, C. none of above, Ans. B, , Que. The inductance offers zero _________ to, DC, A. resistance, B. capacitance, C. reactance, D. permeance, Ans. C, , Que. Inductive reactance, proportional to ________., A. time, B. phase, C. frequency, D. phase difference, Ans. C, , Que. Pure ______ never consumes power, A. resistor, B. inductor, C. starter, D. circuit, Ans. B, , Que. In purely capacitive circuit, current, ______ voltage by 90 degrees., A. lags, B. leads, C. in phase, D. all above, Ans. B, , Que. Inductive reactance is given by_____, A. XL=ωL, B. XL=2πL, C. XL=ΦL, D. XL=ωC, Ans. A, , is, , _________, , is, , directly, , Que. In purely capacitive circuit, current leads, voltageby _______ degrees., A. 30, B. 60, C. 90, 65, , Follow @PuneEngineers | Telegram

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D. 120, Ans. C, , C. XC=1/ΦC, D. XC=2𝝅fL, Ans. A, , Que. The capacitor offers _____ reactance to, DC., A. high, B. low, C. zero, D. none of the above, Ans. A, , Que. ______is given by XC=1/ωL, A. resistance, B. inductance, C. inductive reactance, D. capacitive reactance, Ans. D, , Que. The _________ offers infinite reactance, to DC, A. resistance, B. permeance, C. capacitance, D. none of the above, Ans. C, , Que. Capacitive reactance is measured in, ______, A. farads, B. henrys, C. ohms, D. joules, Ans. C, , Que. The capacitance, _________ to DC, A. resistance, B. capacitance, C. reactance, D. permeance, Ans. C, , Que. Capacitive reactance is _________ to, frequency., A. inversely proportional, B. directly proportional, C. both, C. none of above, Ans. A, , offers, , infinite, , Que. The power curve of pure capacitor is, ________ curve of frequency double than that, of applied voltage, A. sine, B. square, C. tringular, D. sawtooth, Ans. A, , Que. Capacitive reactance, proportional to ________., A. time, B. phase, C. frequency, D. phase difference, Ans. C, , is, , inversly, , Que. Pure ______ never consumes power, A. resistor, B. capacitor, C. starter, D. circuit, Ans. B, , Que. A certain inductor has reactance of 4kΩ, at 5kHz. Its reactance at 15 kHz is _____ kΩ., A. 8, B. 10, C. 12, D. 20, Ans. C, , Que. Inductive reactance is given by_____, A. XC=1/ωC, B. XC=1/2𝝅C, , Que. The square of aj operator _____, A. can never be negative, B. can never be positive, 66, , Follow @PuneEngineers | Telegram

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Que. Consider the sinusoidal waves: A sin, (ωt+30) and B cos(ωt-60). The phase angle, relationship between two waves is:, A. B wave lags A wave by 90 degrees, B. B wave lags A wave by 60 degrees, C. B wave lags A wave by 30 degrees, D. B wave and A wave are in phase, Ans. D, , C. could be either positive or negative, D. is equal to j, Ans. B, Que. A complex number_____, A. is the same as imaginary number, B. has real and imaginary part, C. is negative number, D. is merely a technical term, Ans. B, , Que. Thereactance of L Henryinductance, connected to an AC source of frequency f is, ______ ohm., A. fL, B. πfL, C. 2 πfL, D. all above, Ans. C, , Que. The sum of (3+j6) and (-3-j6) is ____, A. 0+j0, B. 6+j12, C. -6-j12, D. 0-j12, Ans. A, , Que. When pure inductance is connected to an, AC sources, the voltage____ to the current by, ____, A. lags, 90 degrees, B. leads, 90 degrees, C. lags, 45 degrees, D. leads, 45 degrees, Ans. B, , Que. A sinusoidal voltageis represented as: v =, 141.4 sin(314.18t-π/2). Its rms value of, voltage, frequency and phase angle are, respectively____, A. 141.42V, 314.16 Hz, 90 degrees, B. 100V, 50 Hz, -90 degrees, C. 87.92V, 56 Hz, 90 degrees, D. 200V, 50 Hz, -90 degrees, Ans. B, , Que. When a phasor is multiplied by j and –j,, it is rotated through ______ degrees in the, anticlockwise direction respectively., A. 90,270, B. 90,90, C. 90,180, D. 270,90, Ans. A, , Que. When two sinusoidal waves are 90, degrees out of phase, then ____, A. both have their peak values at the same, time, B. both have their minimum values at the same, time, C. one has its peak value, other has zero value, D. none of these, Ans. C, , Que. The p. f. of purely resistive circuit is, ____, A. zero, B. unity, C. lagging, D. leading, Ans. B, , Que. The direction of current in an AC circuit, is _____, A. always in one direction, B. varyingtime to time periodically, C. unpredictable, D. from positive to negative, Ans. B, , Que. If e1 = 100 sin(2πf) and e2 = 100 sin(2πfΦ), then _____, 67, , Follow @PuneEngineers | Telegram

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A. e1 lags e2 by Φ, B. e1 leads e2 by Φ, C. e2 lags e1 by Φ, D. none of the above, Ans. C, , Ans. A, Que. A constant current of 2.8 A exists in a, resistor. The rms value of current is ____, A. 2.8 A, B. 2 A, C. 1.4 A, D. undefined, Ans. A, , Que. The average power in a purely inductive, or capacitive circuit over a cycle____, A. depends on XLor XC, B. is negative, C. is zero, D. is positive, Ans. C, , Que. The power factor of an ordinary bulb is, _____, A. zero, B. unity, C. more than unity, D. less than unity, Ans. B, , Que. Inductive reactance of an AC circuit, increases with ____, A. increase in frequency, B. increase in resistance, C. decrease in resistance, D. decrease in frequency, Ans. A, , Que. When aphasor is multiplied by –j, it is, rotated through ____ in counter-clockwise, direction, A. 90, B. 180, C. 270, D. none of the above, Ans. C, , Que. When the two quantities are in, quadrature, the phase angle between them will, be ____ degrees., A. 45, B. 90, C. 135, D. 60, Ans. B, , Que. If the phasor is multiplied by j, then ____, A. only its magnitude changes, B. only its direction changes, C. both magnitude and direction change, D. none of the above, Ans. B, , Que. The phase difference between two, waveforms can be compared when they _____, A. have the same frequency, B. have the same peak value, C. have the same effective value, D. are sinusoidal, Ans. A, , Que. In the complex number 4+j7, 7 is called, the ______ component, A. real, B. imaginary, C. in-phase, D. none of the above, Ans. D, , Que. If two sinusoids of the same frequency, but of different amplitude and phase difference, are added, the resultant is a ______, A. sinusoid of same frequency, B. sinusoid of double the original frequency, C. sinusoid of half the original frequency, D. non-sinusoid, , Que. The reciprocal of a complex number is, a_____, A. complex number, B. real component only, 68, , Follow @PuneEngineers | Telegram

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A. a complex number, B. in-phase component only, C. quadrature component only, D. none of the above, Ans. C, , C. quadrature component only, D. none of above, Ans. A, Que. If two complex numbers are equal,, then_____, A. only their magnitudes will be equal, B. only their angles will be equal, C. their in phase and quadrature components, will be separately equal, D. none of above, Ans. C, , Que. The reciprocal of j is ____, A. j, B. -j, C. jxj, D. none of the above, Ans. B, , Que. A phasor 2 180 can be expressed, as____, A. j2, B. -j2, C. -2, D. 2, Ans. C, , Que. Two waves of same frequency have, opposite phase when the phase angle between, them is ___ degrees, A. 360, B. 180, C. 90, D. 0, Ans. B, , Que. A current of (3+j4) A is flowing through, a circuit. The magnitude of current is _____, A. 7 A, B. 5 A, C. 1 A, D. 1.33 A, Ans. B, , Que. The power consumed in a circuit element, will be least when the phase difference, between the current and voltageis ____, degrees., A. approx.180, B. approx. 90, C. approx. 60, D. approx. 0, Ans. B, , Que. The voltage applied in a circuit is given, by 100 60 volts. It can be written as ____, A. 100 -60, B. 100 240, C. 100 -300, D. none of the above, Ans. C, , Que. Two sinusoidal currents are given by i1 =, 100sin(ωt+π/3) and i2 = 150sin(ωt-π/4). The, phase difference between them is _____, degrees, A. 15, B. 50, C. 60, D. 105, Ans. D, , Que. The conjugate of -4+j3 is _____, A. 4-j3, B. -4-j3, C. 4+j3, D. none of the above, Ans. B, , Que. Capacitive reactance is more when____, A. capacitance is less and frequency of supply, is less, , Que. The difference of two conjugate number, results in _____, 69, , Follow @PuneEngineers | Telegram

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D. current is in phase with the voltage, Ans. B, , B. capacitance is less and frequency of supply, is more, C. capacitance is more and frequency of, supply is less, D. capacitance is more and frequency of, supply is more, Ans. A, , Que. A phasor is _____, A. a line which represents the magnitude and, phase of an alternatingquantity, B. a line which represents the magnitude and, direction of an alternatingquantity, C. acoloured tag or band for distinction, between different phases of a 3 phase supply, D. an instrument used for measuring phases of, an unbalanced 3 phase load, Ans. B, , Que. Pure inductive circuit ______, A. consumes some power on average, B. does not take power at all from lines, C. takes power from the line during some part, of cycle and returns back during other part of, cycle, D. none of the above, Ans. C, , Que. Ohm is the unit of all the following, except, A. inductive reactance, B. capacitive reactance, C. resistance, D. capacitance, Ans. D, , Que. Power factor of the following circuit will, be zero, A. resistive, B. pureinductive, C. pure capacitive, D. both (B) and (C), Ans. D, , Que. For a purely resistive circuit the, following statement is correct, A. work done is zero, B. power consumed is zero, C. heat produced is zero, D. power factor is unity, Ans. D, , Que. Power factor of the following circuit will, be unity, A. resistive, B. pureinductive, C. pure capacitive, D. both (B) and (C), Ans. A, , Que. For purely inductive circuit if v = Vm sin, (ωt) then equation of current is _____, A. i = Im sin (ωt-π/2), B. i = Im sin (ωt+π/2), C. i = Im sin (ωt-π), D. i = Im sin (ωt+π), Ans. A, , Que. In pure resistive circuit _____, A. current lags the voltageby 90 degrees, B. current leads the voltageby 90 degrees, C. current can lead or lagthe voltageby 90, degrees, D. current is in phase with the voltage, Ans. D, , Que. For purely capacitive circuit if v = Vm, sin (ωt) then equation of current is _____, A. i = Im sin (ωt-π/2), B. i = Im sin (ωt+π/2), C. i = Im sin (ωt-π), D. i = Im sin (ωt+π), Ans. B, , Que. In pure inductive circuit _____, A. current lags the voltageby 90 degrees, B. current leads the voltageby 90 degrees, C. current can lead or lagthe voltageby 90, degrees, 70, , Follow @PuneEngineers | Telegram

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Que. Which of the following statements, pertains to resistor only, A. can dissipate considerable amount of power, B. can act as energy storage device, C. connecting them in parallel increases the, total value, D. opposes sudden change in voltage, Ans. A, , Que. For purely resistive circuit if v = Vm sin, (ωt) then equation of current is _____, A. i = Im sin (ωt-π/2), B. i = Im sin (ωt+π/2), C. i = Im sin (ωt), D. i = Im sin (ωt+π), Ans. C, Que. A sinusoidal voltageV1 leads another, sinusoidal voltage V2 by 180 degrees. Then, ____, A. voltageV2 leads voltageV1 by 180 degrees, B. both voltagehave their zero values at the, same time, C. both voltagehave their peak values at the, same time, D. all of above, Ans. D, , Que. The length of a phasor in a phasor, diagram normally represents the …………, value of the alternating quantity, A. rms or effective, B. average, C. peak, D. none of these, Ans. A, Que. The two quantities are said to be in phase, with each other when, A. the phase difference between two quantities, is zero degree or radian, B. each of them pass through zero values at the, same instant and rise in the same direction, C. each of them pass through zero values at the, same instant but rises in the opposite, directions, D. either (a) or (b), Ans. D, , Que. If A = 10 45 and B = 5 15, then the, value of A/B will be___, A. 50 60, B. 2 60, C. 2 -30, D. 2 30, Ans. D, Que. The active power of AC circuit is given, by ___, A. VI sin Φ, B. I2XL, C. I2R, D. I2Z, Ans. C, , Que. The phase difference between the two, waveforms can be compared only when they, A. have the same frequency, B. have the same peak value, C. have the same effective value, D. are sinusoidal, Ans. A, , Que. Inductance of coil____, A. is unaffected by the supply frequency, B. decreses with the increase in supply, frequency, C. increases with the increase in supply, frequency, D. becomes zero with the increase in supply, frequency, Ans. A, , Que. The phasor diagram for alternating, quantities can be drawn if they have ………, waves, A. rectangular, B. sinusoidal, C. triangular, D. any of these, Ans. B, 71, , Follow @PuneEngineers | Telegram

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Que. The phasor diagram of voltage and, current considering phasors are rotates, clockwise direction is of, , Que. Which of the following statements, associated with purely resistive circuits is, correct?, A. PF is unity, B. Power consumed is zero, C. Heat produced is zero, D. PF is zero, Ans. A, , I, V, , A. Pure resistance, B. pure inductance, C. pure capacitance, D. pure capacitance and pure inductance, Ans. B, , Que. Average power in a pure resistive circuit, is equal to, A. zero, B. product of average values of current and, voltage, C. product of peak values of current and, voltage, D. product of rms or effective values of, current and voltage, Ans. D, , Que. The power factor of an ac circuit lies, between, A. 0 and 1, B. -1 and 1, C. 0 and -1, D. none of these, Ans. A, , Que. The power factor of an ac circuit is equal, to, A. tangent of the phase angle, B. sine of phase angle, C. unity for a resistive circuit, D. unity for a reactive circuit, Ans. C, , UNIT IVB, Que. The period of a certain sine wave is 10, milliseconds. Its frequency is________, A. 10 MHz, B. 10 KHz, C. 10 Hz, D. 100 Hz, Ans. D, , Que. The phasor diagram of voltage and, current considering phasors are rotates, anticlockwise direction is of, I, , Que. The rms value of a sine wave of, maximum value 10A equals a dc current of, ______ampere., A. 7.07, B. 6.37, C. 5, D. 5.77, Ans. A, , V, , A. pure resistance, B. pure inductance, C. pure capacitance, D. pure capacitance and pure inductance, Ans. C, , Que. The rms value of a sinusoidal voltage, with peak-to-peak value of 240 V, is________V., 72, , Follow @PuneEngineers | Telegram

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C. 100V, D. 173.2V, Ans. C, , A. 84.84, B. 77.82, C. 94.68, D. 89.15, Ans. A, , Que. How much rms current does a 300W,, 200V bulb take from the 200V, 50Hz power, line?, A. 0.5 A, B. 1.5 A, C. 2 A, D. 3 A, Ans. B, , Que. The peak value of a sine wave is 400 V., Its average value is_________V., A. 254.6, B. 282.6, C. 400, D. 565.5, Ans. A, , Que. Polar form of v = 100 sin(100πt+π/6), Volt is ________, A. 61.2371+j35.3553, B. 70.7106 30, C. 61.2371 35.3553, D. 70.710+ j30, Ans. B, , Que. The average value of the current 𝑖 =, 𝜋, 200 sin 𝑡 from 𝑡 = 0 to 𝑡 = is ______, 2, A. 400 π, 400, B., , C., , 𝜋, 1, , 400, 𝜋, , Que. Rectangular form of V= 100, sin(100πt+π/6) Volt is ________, A. 61.2371+j35.3553, B. 70.7106 30, C. 61.2371 35.3553, D. 70.710+ j30, Ans. A, , D., 400, Ans. B, Que. An alternating current is given by 𝑖 =, 10 sin 314𝑡. The time taken to generate two, cycles of current is____, A. 0.02 second, B. 0.01 second, C. 0.04 second, D. 0.05 second, Ans. C, , Que. RMS value of current I = 25 + j40 Amp, is _______, A. 57.99, B. 47.1699, C. 60, D. 30, Ans. B, , Que. A sine wave has a frequency of 50 Hz. Its, angular frequency is_______radian/second, A. 100π, B. 50π, C. 25π, D. 5π, Ans. A, , Que. Two currents I1 = 1050 and I2 = 5 100 A flow in single phase AC circuit. Then, I1/I2 =________, A. 5.5596+ j4.924 A, B. 2150 A, C. 7.296+ j12.58 A, D. None of the above, Ans. B, , Que. A sine wave of voltage varies from zero, to maximum of 200V. How much is the, voltage at theinstant of 30° of the cycle?, A. 50V, B. 82.8V, 73, , Follow @PuneEngineers | Telegram

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Que. A 10 mH inductor carries a sinusoidal, current of 1 A at frequency of 50 Hz. The, average power dissipated by the inductor is, ____, A. 0, B. 3.14 W, C. 0.5 W, D. 1 W, Ans. A, , Que. The curve for the instantaneous power, with respect to the waveforms of voltage &, current is shown in figure is of, P, +, , P, +, v, i, 0, , , , , , P, , v, i, 0, , P, , A. pure resistance, B. pure inductance, C. pure capacitance, D. pure capacitance and pure inductance, Ans. C, , p, , p, , , t, , 2, , 2, , Que. The curve for the instantaneous power, with respect to the waveforms of voltage &, current is shown in figure is of, , , , , t, , , , UNIT IVC, Que. An electric iron designed for 110 V, AC supply was rated at 500 W. It was put, across a 220 V, supply. Assuming that at 110 V, it supplied, 500 W output (i.e. no losses) at the new, voltage it will, supply_________, A. 2500 W, B. 2000 W, C. 500 W, D. 250 W, Ans. B, , A. pure resistance, B. pure inductance, C. resistance and capacitance, D. pure capacitance, Ans. A, Que. The curve for the instantaneous power, with respect to the waveforms of voltage &, current is shown in figure is of, P, +, , P, +, v, i, 0, , , , , , , 2, , Que. The mean value of the current 𝑖 =, 𝜋, 20 𝑠𝑖𝑛𝜃 from θ=0 to θ= is_______, 2, A. 40π, 40, B., , , t, , 2, P, , P, , T, , A. pure resistance, B. pure inductance, C. pure capacitance, D. purecapaciatance and pure inductance, Ans. B, , C., , 𝜋, 1, , 40, 𝜋, , D., 40, Ans. B, Que., An ac current is given as i = 10 + 10, sin 314 t, the average and rms values of the, current are____, 74, , Follow @PuneEngineers | Telegram

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A. 16.36 A, 17.07 A, B. 10 A, 17.07 A, C. 10 A, 12.25 A, D. 16.36 A, 12.2 A, Ans. C, , D. 10, Ans. A, Que. If 10 ohm resistor is connected across, an AC voltagev = 100 sin(314t+300), the, power dissipated through resistor is _____, A. 500 W, B. 1000 W, C. 250 W, D. 100 W, Ans. A, , Que., Two currents I1 = 1050 and I2 = 5, -100 A flow in single phase AC circuit. Then, I1+I2 =________, A. 5.5596+ j4.924 A, B. 5.55964.924 A, C. 7.296+ j12.58 A, D. None of the above, Ans. A, , Que. For a frequency of 50 Hz, the, reactance offered by capacitor is 10 ohms, If, the frequency is increased to 100 Hz, the, reactance becomes____, A. 40 ohms, B. 20 ohms, C. 5 ohms, D. 2.5 ohms, Ans. C, , Que., Two currents I1 = 1050 and I2 = 5, -100 A flow in single phase AC circuit. Then, I1-I2 =________, A. 5.5596+ j4.924 A, B. 5.5596 4.924 A, C. 7.296+ j12.58 A, D. None of the above, Ans. C, , Que. Which value of inductance will give, the same reactance as a capacitor of 2 µF when, both are at 50 Hz?, A. 5 H, B. 10 H, C. 15 H, D. 20 H, Ans. A, , Que. In purely inductive circuit, if the, frequency is doubled and applied voltage is, halved, the resulting current becomes____, A. one-fourth, B. one-fifth, C. one-half, D. one-third, Ans. A, , Que. If a 10 ohm resistance is connected to, an AC supply v = 100 sin (314t+370) V, the, power dissipated by the resistance is, A. 10 kW, B. 1 kW, C. 500 W, D. 250 W, Ans. C, , Que. The product of (-4-j7) and (6-j2), is______, A. -24+j14, B. 24-j14, C. -38-j34, D. -24-j14, Ans. C, , Que. A coil has XL = 1000 ohm. If both its, inductance and frequency are doubled, its, reactance will become ___ ohm, A. 2000, B. 500, C. 250, , Que. Inductive reactance of a coil of, inductance 0.2 H at 50 Hz is ____ ohms., A. 62.8, B. 628, C. 0.2, 75, , Follow @PuneEngineers | Telegram

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D. 4000, Ans. D, , A. 5 A, B. 3.18 A, C. 1.57 A, D. 1.10 A, Ans. B, , Que. A pure inductance connected across, 250 V, 50 Hz supply consumes 100 W. This, consumption is due to_____, A. the big size of the inductor, B. the reactance of the inductor, C. the current flowing in the inductor, D. the statement given is false, Ans. D, , Que., An alternating current is given by 𝑖 =, 10 𝑠𝑖𝑛314𝑡. Measuring time from 𝑡 = 0, the, time taken by the current to reach +10 V for, the second time is_________, A. 0.05 second, B. 0.1 second, C. 0.025 second, D. 0.02 second, Ans. C, , Que. A pure capacitor connected across an, AC voltage consumed 50 W. This, A. is due to the capacitive reactance in ohms, B. is due to the current flowing in capacitor, C. is due to the size of capacitor, D. statement is incorrect, Ans. D, , Que. An ac current is given by 𝑖 =, 200 𝑠𝑖𝑛100𝜋𝑡. It will achieve a value of 100A, after_____second., 1, A., , Que. An alternating current of 50 Hz, frequency has a maximum value of 100 A. Its, value 1/600 second after the instant current is, zero will be________, A. 25 A, B. 12.5 A, C. 50 A, D. 75 A, Ans. C, , B., C., , 900, 1, , 800, 1, , 700, 1, , D., 600, Ans. D, Que. The voltage in a circuit follows the, law: 𝑣 = 100 𝑠𝑖𝑛𝜔𝑡. If the frequency is 25, Hz, how long willit take for the voltage to rise, to 50V?, 1, A. S, , Que. A sinusoidal voltage varies from zero, to a maximum of 250 V. The voltage at the, instant of 60° of the cycle will be________, A. 150 V, B. 216.5 V, C. 125 V, D. 108.25 V, Ans. B, , B., C., , 50, 1, , 100, 1, , 300, 1, , S, S, , D. S, 600, Ans. C, , Que. The alternating voltage 𝑒 =, 200 sin 314𝑡 is applied to a device which, offers an ohmic resistance of 20 Ω to the flow, of current in one direction while entirely, preventing the flow in the opposite direction., The average value of the current will, be_________, 76, , Follow @PuneEngineers | Telegram