II/IV B.Tech Degree Examinations, June 2014
First Semester
Electromagnetic Field Theory
Time : 3 hours
Maximum Marks : 60
Answer question No.1 Compulsory
Answer ONE question from each Unit
1. Answer the following [12 x 1 = 12M]
a) Define electric potential.
b) What is the relation between electric field and magnetic field?
c) Define wave polarization.
d) Write the capacitance equation in parallel conductors.
e) Define surface impedance.
f) What is Biot – Savart's law?
g) Define transmission coefficient.
h) Define relaxation time.
i) Define homogeneous and isotropic in dielectrics.
j) What is the relation between electric susceptibility & electric flux density?
k) What is the value of relative permittivity in free space?
l) What s skin depth?
UNIT - I [1 x 12 = 12M]
2. a) Explain the concept of electric field intensity.
2. b) What is a dipole? Derive the expression for torque experienced by a dipole in uniform electric field. (OR)
3. a) A point charge Q=30 nc is located at the origin in Cartesian coordinates. Find the electric flux density 'D' at (6, 8, 0) m.
3. b) State and prove Gauss law. Express Gauss law in both integral and differential forms.
UNIT - II [1 x 12 = 12M]
4. a) Derive Poisson's and Laplace's equation starting from fundamentals.
4. b) Derive the expression for capacitance of a two wire line. (OR)
5. a) Explain equation of continuity for time varying fields.
5. b) Explain the boundary conditions for perfect dielectric materials.
UNIT - III [1 x 12 = 12M]
6. a) State and explain Ampere's circuital law.
6. b) Explain the importance of vector magnetic potential. (OR)
7. a) Explain scalar magnetic potential and give its limitations.
7. b) Explain the nature of magnetic materials.
UNIT - IV [1 x 12 = 12M]
8. a) Derive the expression for displacement current.
8. b) State and explain pointing theorem. (OR)
9. a) A plane wave travelling in air is normally incident on a material with ε_{r}=4 and μ_{r}=1. Find the reflection and transmission coefficients.
9. b) Derive the Maxwell's equations in differential and integral forms.