Microwave Devices and Circuits MCQs

Question 1

The term LASER is an abbreviation for

Accepted Answer

Light amplification by simulated emission of radiation

Answer

Low amplification signal emitting radiowaves

Answer

Last aligned sound emitting radiowaves

Answer

None of the above

Question 2

MASER finds application in

Accepted Answer

Opto electronics

Answer

Fibre optics

Answer

Telephones

Answer

All of the above

Question 3

The skin effect causes current to flow

Accepted Answer

near the surface of the conductor

Answer

in the centre of the conductor

Answer

through central core of the conductor

Answer

uniformly through the conductor

Question 4

In a waveguide the energy is propagated bY

Accepted Answer

varying magnetic and electric fields

Answer

voltage different

Answer

current variations

Answer

varying magnetic fields

Question 5

A duplexer is used

Accepted Answer

to allow the one antenna to be used for reception or transmission without mutual interference

Answer

to couple two different antennas to transmitter without mutual interference

Answer

to prevent interference between two antennas when they are connected to a receiver

Answer

to increase the speed of the pulses in pulses radar

Question 6

Indicate the false statement : Transit time in microwave bubes will be reduced if

Accepted Answer

multiple or coaxial leads are used

Answer

the electrodes are brought closer together

Answer

a higher anode current is used

Answer

the anode voltage is made larger

Question 7

The multi-cavity klystron

Accepted Answer

is not a good low-level amplifier because or noise

Answer

has a high repeller voltage to ensure a rapid transit time

Answer

is not suitable for pulsed operation

Answer

needs a long transit time through the buncher cavity to ensure current modulation

Question 8

The TWT is sometimes preferred to the multicavity klystron amplifier, because the former

Accepted Answer

has a greater bandwidth

Answer

is more efficient

Answer

has a higher number of modes

Answer

produces a higher output power

Question 9

The primary purpose of the helix in a travelling-wave tube is to

Accepted Answer

reduce the axial velocity of the RF field

Answer

prevent the electron beam from spreading in the long tube

Answer

ensure broad band operation

Answer

reduce the noise figure