8/6/2019 EMT Que Paper

1/1

EC 502 ELECTROMAGNETIC THEORY

Time: 3 Hours Maximum marks:100

Part I ( Answer all questions. Each Question carries 5 marks)

1. Explain how a point is represented in cylindrical and spherical coordinate system.

2. Explain the physical significance of Curl.

3. What is meant by polarization?

4. Find out the electric field of a point charge using Gausss law.

5. State and explain Biot-Savarts law.

6. Distinguish between conduction current and displacement current.

7. State and explain Poyntings theorem.8. Explain skin effect.

Part II ( Answer all Questions)

1. (a) Find out the differential elements in cylindrical and spherical coordinate systems. (7)(b) Express the following vector in cylindrical and spherical coordinates. (8)

OR

2. (a) State and prove divergence theorem. (8)(b) Determine the curl of the following vector field. (7)

3. (a) Derive an expression for the electric field intensity of a finite line charge oflength L. (7)

(b) Derive an expression for the potential difference between two points in the field

of a line charge. (8) OR

4. (a) Derive the boundary conditions for electrostatic fields. (8)(b) Using Laplaces theorem obtain the potential distribution between two spherical

conductors separated by a single dielectric. The inner spherical conductor of

radius a is at a potential V0 and the outer conductor of radius b is at potential

zero. Also evaluate the electric field. (7)

5. (a) A circular loop located on x2+y2= 9 carries a direct current of 10 A along direction. Determine magnetic field at (0,0,4) and (0,0,-4). Derive the equations

used. (8)

(b) Find the expression for the inductance of a solenoid. (7)

OR

6. (a) Derive the expression for the magnetic field of a coaxial cable. (8)(b) State and explain Faradays laws of electromagnetic induction. (7)

7. (a) List and explain all Maxwells equations in integral and point form. (7)(b) Derive wave equations for free space. (8)

OR

8. (a) Derive the expression for reflection coefficient and transmission coefficient for a

normally incident wave with parallel polarization. (8)

(b) Explain the transmission of plain waves in lossless dielectrics. (7)

2 2 2

x y z F xy za x yza xyz a= + +

2

1 T cos sin cos cosra r a a

r

= + +r