Transmission Lines and Waveguides MCQs

Question 1

A lossless transmission line is excited by a 200 MHz signal. If the dielectric constant is 2.25, the phase shift constant is

Accepted Answer

2 71 rad/m

Answer

TE rad/m

Answer

1.5 rad/m

Answer

none of the above

Question 2

One of the following statements is wrong

Accepted Answer

The propagation velocity on the transmission line is inversely proportional to the permittivity of the dielectric used

Answer

When a given transmission line is terminated in its characteristic impedance, its input impedance is always equal to the characteristic impedance irrespective of the length of the line in terms of wavelength

Answer

When a transmission line is terminated in an impedance other than the characteristic impedance, its input impedance varies with length for a givensignal frequency or with frequency for a given length

Answer

The characteristic impedance of a lossless line is resistive

Question 3

With reference to transmission lines, the normalised load impedance is determined by

Accepted Answer

dividing the load resistance by characteristic impedance of the line

Answer

the product of load resistance and the characteristic impedance of the line

Answer

dividing the resistance value by 100

Answer

none of the above

Question 4

A 50 fl transmission line is terminated in a load impedance of (50 + j 100) a The normalised load impedance is

Accepted Answer

(1 + j 2) C2

Answer

(2500 + j 5000)0

Answer

(0.5 +j)

Answer

none of the above

Question 5

The arcs of circles on smith chart represent

Accepted Answer

normalised reactances or susceptances

Answer

normalised resistnace or conductances

Answer

different values of SWR

Answer

none of the above

Question 6

Smith chart can be used to determine

Accepted Answer

all of the above

Answer

SWR for any given transmission line-load mismatch

Answer

magnitude and angle of reflection co-efficient

Answer

the length of short circuited transmission line section of known characteristic impedance to provide the desired input impedance

Question 7

The phase velocity in a transmission line is

Accepted Answer

v =L

Answer

v = 17

Answer

v =1

Answer

v = LC

Question 8

The Q of a resonant transmission line is

Accepted Answer

Q =R

Answer

Q = -R

Answer

Q = coR

Answer

Q=R

Question 9

The measure of mismatchbetween the load and the. transmission line is known as

Accepted Answer

Reflection coefficient

Answer

Directivity

Answer

(1 ?Gain)

Answer

Standing wave ratio