JNTU Kakinada B-Tech 2-2 RT22044 EM WAVES AND TRANSMISSION LINES R13 April 2018 Question Paper

Code No: RT22044
II B. Tech II Semester Supplementary Examinations, April-2018
EM WAVES AND TRANSMISSION LINES
(Com to ECE, EIE)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answer ALL the question in Part-A
3. Answer any THREE Questions from Part-B
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1. a) Define magnetic torque and magnetic dipole moment. (4M)
b) What is Faraday?s law of electromagnetic induction? (3M)
c) Define loss tangent and loss angle. Explain the significance of these terms. (4M)
d) What is Poynting vector? What is the physical interpretation of this vector? (4M)
e) Sketch E and H fields in coaxial transmission line. (3M)
f) Explain how standing wave ratio is calculated using smith chart. (4M)
PART -B
2. a) What do you mean by electric dipole and derive the expression for electric field
due to dipole with center at the origin. (8M)
b) In free space, the magnetic flux density B = y
2
a
x
+ z
2
a
y
+ x
2
a
z
Wb/m
2
i) Find the magnetic flux through x = 1, 0 < y < 1, 1 < z < 4. (8M)
3. a) Write down the integral and differential forms of Maxwell?s equations and write
their physical significance. (8M)
b) A parallel plate capacitor with plate area of 5 cm
2
and plate separation of 3 mm
has a voltage 50 sin 10
3
t applied to its plates. Calculate the displacement current
assuming ? = 2?
0
. (8M)
4. a) Explain about wave propagation in free space. (8M)
b) An EM wave propagating in a certain medium is described by E = 25 sin(2p x 10
6
t
? 6x)a
z
V/m (i) Determine the direction of wave propagation. (ii) Compute the period T, the wavelength ? and the velocity (iii) Sketch the wave at t = 0, T/8, T/4, T/2. (8M)
5. a) Discuss about reflection and refraction of plane waves for oblique incidence with
E parallel to the plane of incidence. (8M)
b) A plane wave travelling in free space is normally incident on the interface with a
perfect dielectric with ?
r
= 3. Compute the magnitudes of incident, reflected and
transmitted E and H at the interface. Take E
i
= 1.5 mV/m in medium 1. (8M)
6. a) Discuss about lossless and distortionless transmission lines. (8M)
b) A transmission line operating at 500 MHz has Z
0
= 80 ?, a = 0.04 Np/m and ? =
1.5 rad/m. determine the line parameters R, L, G and C. (8M)
7. a) Explain about Single stub matching. (8M)
b) Explain load matching using quarter wave transformer. (8M)
1 of 1
SET – 1
R13