II/IV B.Tech Degree Examinations, January 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) State Ampere's law.
b) What are the units of electric flux density?
c) Write the Maxwell's equations in static fields.
d) What are the charge distributions in magnetic field?
e) Write the capacitance equation in coaxial cable.
f) Write the vector magnetic potential equation.
g) What is reluctance?
h) Define magnetization in magnetic field.
i) Define convection current density.
j) Define skin depth.
k) Define reflection coefficient.
l) Define intrinsic impedance in good conductor.
UNIT - I [1 x 12 = 12M]
2. a) State and explain Coulomb's law in vector form.
2. b) Derive the expression for force on a point charge due to group of charges. (OR)
3. a) State and explain Gauss law. Give its applications.
3. b) Explain clearly the difference between potential and potential difference.
UNIT - II [1 x 12 = 12M]
4. a) Derive Poisson's and Laplace's equations.
4. b) Find the capacitance of a parallel plate capacitor with a dielectric mica filled between plates with ε_{r} = 6. The plates of the capacitor are square in shape with 0.254cm side. Separation between the plates is 0.254cm. (OR)
5. a) Obtain the boundary conditions at the boundary of two dielectric materials.
5. b) Derive the expression for continuity of current.
UNIT - III [1 x 12 = 12M]
6. a) Derive the expression for the energy stored in magnetic field.
6. b) Explain different magnetic materials. (OR)
7. a) State and derive Biot – Savart's law.
7. b) Derive the expression for force between two current elements.
UNIT - IV [1 x 12 = 12M]
8. a) State and explain Maxwell's equations in integral and point form.
8. b) Derive the wave equation in free space. (OR)
9. a) State and explain pointing theorem. Give its applications.
9. b) What is meant by polarization of wave? When the wave is linearly polarized and circularly polarized.