Microwave Engineering Lab Viva Questions 2

1. A transmission line of characteristic impedance 50 Ohm operating on 3 GHz, is terminated by a load impedance of 60+j10 Ohm. Find the input impedance at a distance 2.5 cm from the load along the line.

a) 40.5 + j6.76

b) 60 + j10

c) 40.5 - j6.76

d) 60 - j10

Answer : [C] 40.5 - j6.76

2. On a transmission line the distance between Vmax and Vmin of the standing wave is

a) λ/2

b)λ/4

c) λ

d) None of these

Answer : [b] λ/4

3. In a smith chart one complete rotation in anticlockwise represent

a) λ/2 towards generator

b) λ towards load

c) λ/2 towards load

d) λ towards generator

Answer : [C] λ/2 towards load

5. On a terminated transmission line, given that Vmax=10mV, Vmin=5 mv, what is the magnitude of the reflection coefficient(|Γ|)

a) 3

b) 0.33

c) 0.5

d) Data is not sufficient

Answer : [B] 0.33

7. What is the cut of frequency of a waveguide with dimensions a=2.5 c.m and b=1 c.m and operating in TE11 mode

a) 16.15 GHz

b) 161 MHz

c) 32.3 GHz

d) 323 MHz

Answer : [A] 16.15 GHz

8. Which of the following Modes do not exist in a waveguide

a) TE11

b) TE01

c) TM11

d) TM01

Answer : [D] TM01

9. Which of the following transmission line operates on quasi-TEM mode

a) Twisted pair

b) Coaxial Line

c) Waveguide

d) Micro strip Line

Answer : [D] Micro strip Line

10. If c is the velocity of a wave in free space then the phase velocity of the same wave in a waveguide is

a) Less than c

b) Greater than c

c) equal to c

d) Independent of c

Answer : [b] Greater than c