# Mumbai University Previous year question papers

## V Sem Electronics Examination Dec 2012

## Electromagnetic Engineering

N. B.: (1) Question No.1 is compulsory.

(2) Attempt any four questions from Question Nos. 2 to 7.

(3) Vector notation should be used wherever necessary.

(4) Assumptions made should be clearly stated.

I. (a) Explain loss less propagation. 5

(b) State and explain Poynting theorem. 5

(c) Derive wave equation for homogeneous unbounded source free medium starting from Maxwell’s equation.

(d) Write a note on Smith Chart. 5

2. (a) Obtain the transmission line equations for a two wire transmission line. Define characteristic impedance of the transmission line. Derive an expression for its characteristic impedance.

(b) Using Smith Chart tind the input impedance and reflection coefficient at a point 0·64A. from load ZL = (75 – j 25) ncharacteristic impedance is 50 n..

3. (a) Explain various types of electromagnetic interferences. 10

(b) Derive Maxwell’s equation in integral form. 10

4. (a) State and prove the Poynting theorem. Explain the integrals involved in the statement. 10

(b) Explain reflection of uniform plane wave at normal incidance. 10

5. (a) What is need of Electromagnetic Compability ? 6

(b) Explain Divergence theorem. 4

(c) Explain potential functions for sinusoidal radiation oscillations. 10

6. (a) Derive the expressions for the reflection and transmission coefficients in case of reflection from perfect dielectric at –

(i) Normal incidence

(ii) Oblique incidence (parallel polarization).

(b) A loss less 50 n transmission line is terminated in 25 + j SO n. Find – 10

(i) Voltage reflection coefficient

(ii) Current reflection coefficient

(iii) VSWR

(iv) Impedance at 0·3 A. distance from the load.

7. Write short notes on ;- 20

(a) Helmoltz Equations

(b) Gauss’s Law

(c) Poisson’s Equation

Cd) Impedance Matching