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Objective Questions, Multiple Choice Questions, 1. Unit of electrical potential is, 7. The potential of an electric dipole, varies with distance r as, (a) JIC, (b) J-C, (), W-A (), w-ar Ip), 2. A charge Q is placed at the origin. The, electric potential due to this charge at a, given point in space is V. The work, done by an external force in bringing, another charge g from infinity upto the, point is, 8. The potential in the equatorial plane of, a dipole having dipole moment p is, (al infinite, (c) maximum, (bi zero, do enbe (P), 9. Two equal and opposite charges, (+g and -9) are situated at a distance x, from each other. The value of potential, at very far point will depend upon, bA (9), A (P), DIA (), If 100 J of work has to be done in, moving an electric charge of 4 C from a, place, where potential is-10 V to, another place where potential is Vvolt,, find the value of V, (a) 5V, (c) 25 V, (b) only on x, buo Auo (e), gu (P), 10. In a region of constant potential,, x-buo (), (NCERT Exemplar), (b) 10 V, Id) 15 V, (a) the electric fieid is uniform, (b) the electric field is zero, (c) there can be no charge inside the region, (d) the electric field shall necessarily change, if, 4. The electric potential due to point, charge 3nC at distance of 9 cm is, (b)3 V, Id)30 V, uoiba au apisano peoejd si eJey e, (a)270 V, (c) 300 V, 11. A positively charged particle is released, from rest in an uniform electric field., The electric potential energy of the, charge, la) remains a constant because the electric, field is uniform, (b) increases because the charge maves along, the electric field, tel decreases because the charge moves along, the electric field, (di decreases because the charge maves, opposite to the electric field, 5. A metallic hollow spherical surface of, radius 5 cm is charged such that the, potential on its surface is 10 V. The, potential at the centre is, (NCERT Exemplar), la) zero, AGL (4), Ic) same as at a point 5 cm away from the, surface, (a) same as at a point 25 cm away from the, surface, 12. 4, B and Care three points in a uniform, electric field, the electric potential is, 6. The potential of a large liquid drop, when eight liquid drops are combined, is 20 V, then the potential of each, single drop was, (a) 10 V, Idl 2.5V, AS (0

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CBSE New Pattern ~ Phystes 12th, 30, 18. If a conductor has a potential V, there are no charges anywhere else, outside, then, la) there must be charges on the, inside itself, (b) there cannot be any charge in the body, the conductor, (c) there must be charges only on the surfs, (d) there must be charges inside the surface, CBSE New Patte, (a) maximum at A, (b) maximum at B, (c) maximum at C, (d) same at all the three points A, B and C, surface or, 13. Equipotential surfaces at a great, distance from a collection of charges, whose total sum is not zero are, The charge, difference, (a) 178 x10, (b) 178 x 10, (c) 4.3x10, (d) 2 x10, (NCERT Exemplar), approximately, (a) spheres, (b) planes, 19. The graph shows the variation of, voltage Vacross the plates of two, capacitors A and B versus increase of, charge Q stored in them. Which of the, capacitors has higher capacitance?, 23. An air ca, amount, oil tank., electric, capacito, (a) incre, (b) decr, (c) rema, (d) becc, (d) ellipsoids, (c) paraboloids, 14. The electrostatic potential energy, between proton and electron separated, by a distance of 1 A is, (a) 13.6 eV, (c)-14.4 eV, (b) 27.2 eV, (d) 1.44 eV, 15. The electric potential of earth is taken, to be zero, because earth is a good, Ve, VA, 24. A para, (a) insulator, (c) semiconductor, (b) conductor, (d) dielectric, caрас, betwe, dielee, 16. Suppose a system of two charges as, shown below placed in an external, electric field, (a) Capacitor A, (b) Capacitor B, (c) Both have same capacitance, (d) None of the above, capac, diele, (), E = A, where A =9 x 10 C/m2, (a) 4, (c) 1, What would be the electrostatic energy, of the configuration?, 20. Two plates of capacitors are at, potentials - 10 V and + 30 V. If the, separation between the plates be 2m,, the electric field between them is, 25. A p, two, E, die, lal 20 V/m, (c) 50 V/m, (b) 10 V/m, (d) 30 V/m, (91-2 uC), (-9 cm, 0, 0), (9 cm, 0, 0), 21. The electric potential difference, between two parallel plates is 2000 V.I, the plates are separated by 2 mm, then, what is the magnitude of electrostaticme, force on a charge of 4 x10-6 C located., mid-way between the plates?, 12, (a) 49J, (c)-49.3J, (b) 49.3 J, (d) 45J, Goole, 17. An electric field of 1000 V/m is applied, to an electric dipole at angle of 45°., The value of electric dipole moment is, C-m. What is the potential, (a) 4 N, 10-29, energy of the electric dipole?, (a) -9x10-20 J, (c) -20 x10-1 J, (b) 6 N, (d) 15x10 N, 22. A parallel plate capacitor has circular, plates of radius 8 cm and plate s, (c) 8N, 26., (b)-10 x 10-29 J, (d) -7x10- J, separation 1 mm.

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2539, 31, The charge on the plates, if potential, difference of 100 V applied is, (al 178 x10 C, (cl 4.3x10 C, idl 2x10C, 27. Three capacitors 3uF, 6uF and 6uF are, connected in series to a source of, 120 V. The potential difference (in volt), across the 3uF capacitor will be, 25, An air capacitor is charged with an, amount of charge g and dipped into an, oil tank. If the oil is pumped out, the, electric field between the plates of, capacitor will, 0 (a), 09 (P), 28. Capacitance between points A and B is, ial increase, Ib) decrease, (c) remain the same, idl becomes 2ero, 2F, 3WF, 24. A parallel plate air capacitor haa a, capacitance 18 µF. If the distance, between the plates is tripled and a, dielectric medium is introduced, the, capacitance becomes 72 µF. The, dielectric constant of the medium is, 12,, y (), pe, 1., AF, 12, 6 (Q), (d) 2, 29. In the figure shown, the effective, capacitance between the points A and, B, if each has capacitance C, is, 28, (c) 12, bor, 25. A parallel plate capacitor is made of, two dielectric blocks in series. Effective, dielectric constant K is, (NCERT Exemplar), u ba, 33, ip, la) 20, (9), (c) 5C, Kp+ Kd, Kd+Kg, (P), (1), K,+K2, 30. A parallel plate capacitor is made by, stacking n equally spaced plates, connected alternately. If the, capacitance between any two plates is, C, then the resultant capacitance is, (a) C, (cl In-1C, (e), p+'p, 2KK, 26. Three capacito s each of capacitance C, and of breakdown voltage V are joined, in series. The capacitance of the, combination will be, Ju (9)