Wave Theory & Propagation - Dec 2014

Electronics & Telecomm. (Semester 4)

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.

Attempt any four out of the five:-

1 (a) Write integral from of Amperes Law and interpret the same.(5 marks) 1 (b) Define Intrinsic Impedance. Calculate its value for free space.(5 marks) 1 (c) Give and explain various steps involved in finding characteristics impedance for micro-strip line using finite difference Method.(5 marks) 1 (d) What do you mean by Depth of pentration.(5 marks) 1 (e) What is loss Tangent. Explain how it classifies lossless dielectrics, lossy Dielectric and good conductor.(5 marks) 2 (a) Derive Maxwells equation in point form and integral form.(10 marks) 2 (b) Compare FDM, FEM & MOM.(5 marks) 2 (c) Compare scalar and vector potential.(5 marks) 3 (a) In certain Medium [ ?ar{E}= left [ 10e^{-0.05x} sin left ( 2 imes 10^8 t-2x ight ) ight ]?ar{a}_2 v/m Find: ]
i) Propagation constant
ii) Wavelength
iii) Speed of wave
iv)Skin Depth(10 marks) 3 (b) Derive wave equation for good dielectric medium.(5 marks) 3 (c) Give Boundary conditions for Electric and magnetic field for interface between good conductor and dielectric.(5 marks) 4 (a) Use method of moment to find the capacitance of parallel plate capacitor of figure 1. Take a=1 meter; b=1 meter; d=1 meter and &epsilon_r=1. (10 marks) 4 (b) Derive an expression for magnetic field intensity due to finite long straight element.(10 marks) 5 (a) What do you mean by Fading? How it can be minimized?(5 marks) 5 (b) Write a short note on Ionospheric Propagation.(5 marks) 5 (c) Explain Super Refraction and Tropospheric Fading.(10 marks) 6 (a) Prove that static electric field is irrotational ans static magnetic field solenoidal.(10 marks) 6 (b) Explain Reflection of Uniform Plane wave at Oblique Incidence.(10 marks)