Radar Engineering and Satellite Communication MCQs

Question 1

An accentricity figure of greater than unity would imply that

Accepted Answer

the satellite escapes from the orbit

Answer

the satellite orbit becomes elliptical

Answer

the satellite orbit becomes parabolic

Answer

none of these

Question 2

Mark the wrong statement

Accepted Answer

an inclined polar orbit can never be a geosynchronous orbit

Answer

All geostationary orbits are geosynchronous orbits where as all geosynchronous orbits are not geostationary orbits

Answer

Molniy9 orbbit is popular with Russian communication satellites

Answer

A spin stabilised satellite uses a simple technique for stabilisation or attitude control but larger number of solar cells whereas a body stabilised satellite uses a very complex stabilisation mechanism but a fewer solar cells

Question 3

With reference to Q-59, if (a) is the semi-major axis of elliptical transfer orbit and (r) is the distance of a given point on the orbit from the centre of earth, ther the orbital velocity of the satellite at that point is given by (IL = GM)

Accepted Answer

u = 1(21t- ?a)

Answer

u =?r a

Answer

u2 = (-Lir ?)

Answer

u =a

Question 4

The orbital velocity at the apogee point in an eccentric elliptical orbit increases when the elliptical orbit is transformed into a circular orbit with apogee point remaining the same. This increment in velocity is the minimum when

Accepted Answer

elliptical orbit and circular orbit are in the same plane

Answer

elliptical orbit plane is indined at 45? to the circular orbit plane

Answer

elliptical orbit plane is at right angles to the circular orbit plane

Answer

none of these

Question 5

Molniya orbit serves the purpose of a geosynchronous orbit for high latitude regions. The number of satellites usually required at different phases of the same Molniya orbit to provide uniterrupted service to a given area is

Accepted Answer

3

Answer

6

Answer

1

Answer

4

Question 6

For satellite communication, the frequency should be the critical frequency of ionosphere.

Accepted Answer

come than

Answer

equal to

Answer

less than

Answer

none of the above

Question 7

Before transmitting to the satellite, the wide-band satellite signal is apmplified bY

Accepted Answer

travelling wave tube

Answer

waveguide

Answer

klystron

Answer

any of the above

Question 8

A satellite repeater serves which of the following purposes?

Accepted Answer

It translates the signal to new frequency band

Answer

It receivers signal from the satellite

Answer

It repeats the satellite signals many times

Answer

None of the above

Question 9

The telephone channels in a communication satellite are assembled in

Accepted Answer

FDM

Answer

FM

Answer

AM

Answer

TDM