Radar Engineering and Satellite Communication MCQs

Question 1

A 20-m antenna gives a certain uplink gain at frequencies of 4/6 GHz. For getting same gain in the 20/30 GHz band, antenna size required is metre

Accepted Answer

4

Answer

100

Answer

1

Answer

10

Question 2

Which of the following statement regarding link loss fur_ a satellite link is wrong?

Accepted Answer

loss in down link is negligible as compared to that in uplink

Answer

for fixed antenna size, it is inversely proportional to f2

Answer

for fixed frequency, it is inversely proportional to the product of the antenna aperture are as

Answer

for a given satellite operating at a given frequency, it is inversely proportional to area of the earth station antenna

Question 3

To make an antenna more directional, either its size must be increased or

Accepted Answer

the frequency of its transmission must be increased

Answer

the number of its feed horns must be increased

Answer

its effective isotropic radiated power (EIRP) must be increased

Answer

its footprint must be increased

Question 4

Shannon's Law relates

Accepted Answer

information carrying capacity to S/N ratio

Answer

antenna gain to frequency

Answer

noise power to bandwidth

Answer

transmission losses to noise

Question 5

Noise temperature of Sun is more than

Accepted Answer

1,00,000

Answer

1000

Answer

5000

Answer

500

Question 6

The noise temperature of sky is about ?K

Accepted Answer

30

Answer

100

Answer

273

Answer

0

Question 7

The average noise temperature of Earth, as viewed from space, is

Accepted Answer

254

Answer

303

Answer

100

Answer

500

Question 8

While keeping the down-link frequency constant, the diameter of a satellite antenna is reduced by half. To offer the same EIRP over the increased coverage area, the RF output power has to be increased by a factor of

Accepted Answer

4

Answer

2

Answer

8

Answer

16

Question 9

The quality of a space-link is measured in terms of the ratio.

Accepted Answer

C/N

Answer

Snsl

Answer

G/T

Answer

EIRP