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QUESTION BANK OF ENGINEERING PHYSICS (KAS -101T), Unit-II, Electromagnetic Field Theory, By-Dr. Pravin Kumar Singh, Assistant Professor (Physics), , SHORT ANSWER TYPE QUESTIONS:, Low Difficulty level Questions, 1. What is displacement current?, 2. Write Maxwell’s equations both in integral and differential forms., 3. Write down the four Maxwell’s equation in free space?, 4. What is Poynting theorem?, 5. What do you mean by Skin depth or depth of penetration?, Moderate Difficulty level Questions, 6. Why Maxwell proposed that Ampere’s law required modification., 7. What do you mean by impedance of a wave?, 8. A dielectric medium is kept in variable field. Show that the value of displacement current is, equal to theconduction current., High Difficulty level Questions, 9. Give the physical significance of Maxwell’s equations., 10., , ⃗⃗ in a plane wave is 5 amp/meter, find the magnitude of E, ⃗ for plane, If the magnitude of H, wave in free space., , 11., , What is physical significance of Poynting theorem., , LONG ANSWER TYPE QUESTIONS:, Low Difficulty level Questions, 1., , State and explain Poynting theorem (Work energy theorem) for the flow of energy in, electromagnetic waves, , 2., , Write down the Maxwell’s equation in free space and prove that the velocity of plane, electromagnetic wave in the vacuum is given by c =, , 3., , 1, √μ0 ε0, , ., , If the upper atmosphere layer of earth receives 2.73 Kw/m2 energy from sun what will be, the peak valueof electric and magnetic fields at the layer., , 4., , A 500 watt sodium lamp radiating its power. Calculate the electric and magnetic field, , 1

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strength at adistance of 7m from the lamp., , Moderate Difficulty level Questions, 5., , What is skin depth? Discuss the depth of penetration of the wave in a conducting medium., , 6., , Write down Maxwell’s equation in free space and show that E, H vectors are normal to each, other and to the direction of propagation of the wave., , 7., , State and Prove Maxwell’s four differential and integral equations., , 8., , If earth receives 7 cal/min-cm2 solar energy what are the amplitude of electric and magnetic, fields ofradiations., , 9., , Assuming that all the energy from a 700 watt lamp is radiated uniformly, calculate the average, valuesof the intensities of electric and magnetic fields of radiation at a distance of 2m from, the lamp., ., , High Difficulty level Questions, 10. Explain the concept of displacement current and show how it led to the modification of the, Ampere’slaw., 11. The permeability, permittivity and conductivity of aluminium are µr = 1 , ϵr = 1 and 𝜎 = 3.54, 107.Findthe skin depth if the wave enter in aluminium with frequency 72 MHz., 12. A material have the conductivity of 10-3 s/m and ϵr=2.5. If electric intensity is E= 4.5 x 10-6, Sin(8 xx109t). Then find the conduction and displacement current., 13. Calculate the depth of penetration at the frequency 71.6MHz in aluminium. The permeability, andconductivity for aluminium are 4𝜋 x 10-7 N/Amp2 and 3.54 x 107 siemens/m respectively., , 2