M.Sc. DEGREE EXAMINATION, NOVEMBER 2017
Second Semester
Physics
ELECTROMAGNETIC THEORY
(CBCS 2014 onwards)
Time 3 Hours Maximum 75 Marks
Part A (10 x 2 20)
Answer all questions.
1. Can a charged particle be help in stable equilibrium by
electrostatic force alone? Explain your answer.
2. Define equation of continuity.
3. "Like Gauss's law Ampere's law is always true, but it is
not always useful". Justify this statement.
4. Differentiate magnetic susceptibility from permeability.
5. Is there a displacement current in a good conductor?
Why?
6. What do you infer from first Maxwell's equation?
7. How a cut off mode arise in wave guide?
8. Show that electromagnetic waves are transverse.
9. Define the term "radiation resistance".
10. When is an EM radiation said to be bremstrahlung?
Sub. Code
4MPH2C2
AFF-4864
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Part B x 5 25)
Answer all questions by choosing either or
11. State and prove Gauss' law.
Or
Obtain an expression for potential energy due to
point charge distribution and continuous charge
distribution.
12. Deduce an expression for the magnetic vector
potential.
Or
Use the Biot-Savart law to compute the magnetic
induction B at the centre of a square current loop
carrying a current.
13. State and prove poynting's theorem.
Or
Give both the integral and differential forms of
Faraday's law. Also explain briefly the Faraday's
emf.
14. Explain the propagation of plane electromagnetic
waves through a linear, isotropic, homogeneous and
stationary media.
Or
The index of refraction of diamond is 2.42. Calculate
the critical angle and
the brewsters angle.
AFF-4864
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15. Explain the radiation field of an magnetic dipole.
Or
Discuss the scattering by free electrons.
Part C x 10 30)
Answer any three questions.
16. Discuss in detail the lapalce equation in one and
two dimensions.
Describe the electrostatic boundary conditions.
17. Compare electrostatics with magnetostatistics.
Deduce Lorentz force.
18. What are Gauge transformations? Obtain the Lorentz
and Coulomb Gauge conditions.
19. Discuss the propagation of TE wave through a
rectangular hollow metal pipe.
20. How will you determine the retarded potential satisfies
the in homogeneous wave equation?