Question Paper: Electromagnetic Engineering : Question Paper Dec 2015 - Electronics Engineering (Semester 5) | Mumbai University (MU)
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## Electromagnetic Engineering - Dec 2015

### Electronics Engineering (Semester 5)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

### Solve any four:

1 (a) State and explain Coulomb's law.(5 marks) 1 (b) Derive Poisson's and Laplace equation.(5 marks) 1 (c) What is intrinsic impedance of free space?(5 marks) 1 (d) Define directive gain and directivity with respective antenna. An antenna has a directivity of 20 and a radiation efficiency of 90% compute the gain in dBs.(5 marks) 1 (e) Find out the divergence and curl of the following function. $$\overline{A}=2xy\overline{ax}+(x^2z)\overline{ay}+z^3 \overline {az}$$(5 marks) 2 (a) Given the potentials V=2x2y-5xz and a point P(-4, 3, 6) find V,E,D and e, at point P.(10 marks) 2 (b) Derive boundary conditions for electric fields at the boundary of two dielectric media.(10 marks) 3 (a) Derive Maxwell's integral and point form equations for time varying fields.(10 marks) 3 (b) Prove $\nabla, \overline{D} = e_v.$(10 marks) 4 (a) In a media characterized by σ=0, μ=μ0 and ε=ε0 $$\overline{E}=20 \sin (10^8 t-\beta z)\overline {ay} \ \text{v/m.} \text{ find}\beta \text{ and }\overline {H}.$$(10 marks) 4 (b) Derive the expression for the reflection and transmission coefficients in case of reflection from perfect dielectric at oblique incidence.(10 marks) 5 (a) Explain in detail MOM method also state advantage and drawback of it.(10 marks) 5 (b) State and derive the Poynting theorem and describe the significance of each term.(10 marks) 6 (a) What is line of sight propagation? Obtain the expression for range of line of sight for space wave propagation in terms of antenna's transmitting and receiving heights.(10 marks) 6 (b) Explain ground wave, space wave propagations.(10 marks) 6 (c) Derive an expression for radiation resistance of an small loop antenna. Explain its significance.(10 marks)