SPPU Electronics and Telecom Engineering (Semester 5)
Electromagnetics and Transmission Lines
December 2016
Total marks: --
Total time: --
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Solve any one question from Q.1(a,b,c) & Q.2(a,b,c)
1(a) Derive expression for fllux density for an infinite line charge using Gauss law.
8 M
1(b) Derive relation betweenE and V. Also state significance of potential gradient.
8 M
1(c) State & explain strokes theorem.
6 M

2(a) A point charge of 2nC is located at (4, -1, -3) & a uniform line charge of -25nC/m lies along the intersection of phases X = -4 & Z=6 calculate \[\bar{D} \text{and} \bar{E}\text{at}(3,1,0).\]
8 M
2(b) derive boundary condition for perfect dielectric media.
8 M
2(c) In the region 0\( \bar{J}=4.5e^{-2x}a_z\left ( \frac{A}{m^2} \right )\text{and }J=0\)/ elsewhere. Use Ampere's law to find \[\bar{H}\].
5 M

Solve any one question from Q.3(a,b) & Q.4(a,b)
3(a) What is pointing vector? What is its significance ? Derive the expression for average pointing vector.
8 M
3(b) In free space \( \bar{E}=20\cos \left ( wt-50x \right )\overline{ay}V/m \)/ determine:
i) Id ii) H
iii) W
8 M

4(a) Write Maxwell's equation on the basis of Ampere's circuit law in integral as well as differential form and modify the above equation for sinusoidal time varying field in free space.
8 M
4(b) A boundary condition exists at Z =0 between dielectrics ∈r1=2.5 region Z<0&∈r2=4 in the region Z>0. The field in the region of ∈r1 is \( \bar{E}=-30\overline{ax}+50\overline{ay}+70\overline{az}\frac{V}{m} \)/ Find:
i) Normal component of E1. ii)Tangential component of E1.
iii) Angle α1 between E1 & normal to surface.
iv) Normal component of D2. v) Tangential component of D2.
vi) Angle α2 between D2 & normal to surface.
8 M

Solve any one question from Q.5(a,b) & Q.6(a,b)
5(a) Defien various parameters of transmission line.
6 M
5(b) What are the different types of distortion? Derive the condition for Inductance loading on Telephone cable.
10 M

6(a) Derive the equation for volatage & current of general solution of transmission line.
10 M
6(b) Prove that \[Z_0=\sqrt{Z_{oc}Z_{sc}}.\]
6 M

Solve any one question from Q.7(a,b) & Q.8(a,b)
7(a) Derive expression for characteristic impedance, propagation constant and velocity of propagation for distortion less line.
8 M
7(b) A transmission line with characteristics impedance of 692∠-12°Ω is terminated in 200Ω resistor. Determine reflection coefficient & SWR.
10 M

8(a) What do you mean by single stub matching on a line and derive the equation of single stub along the line.
8 M
8(b) In lossless 100Ω transmission line is terminated in an impedance 50+j60Ω. Calculate VSWR, reflection coefficient, impedance of 0.35λ from the load using smith chart.
10 M

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