Microwave Devices and Circuits MCQs

Question 1

For a rectangular waveguide having, having a as broader dimension and b as narrow dimension, the cut off wavelength for TElo will be

Accepted Answer

2 b

Answer

a

Answer

b

Answer

2 a

Question 2

The cavity magnetron uses strapping to

Accepted Answer

prevent mode jumping

Answer

prevent cathode back heating

Answer

ensure bunching

Answer

improve the phase-focusing effect

Question 3

Waveguides are not feasible at low frequencies because the circuit dimensions are

Accepted Answer

small compared to a wavelength

Answer

large compared to a wavelength

Answer

both (a) and(b)

Answer

none of the above

Question 4

Which diode does not use negative resistance for its operation

Accepted Answer

Backward

Answer

Gunn

Answer

IMPATT

Answer

Tunnel

Question 5

A magnetic field is used in the cavity magnetron to

Accepted Answer

ensure that the electrons will orbit around the cathode

Answer

ensure that the oscillations are pulsed

Answer

prevent anode current in the absenceof oscillations

Answer

help in focusing the electron beam, thus preventing spreading.

Question 6

At different frequencies microwave impedance measurement is possible with the help of

Accepted Answer

a spectrum analyzer

Answer

a travelling detector and other auxiliary apparatus

Answer

either of the above

Answer

none of the above

Question 7

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

Accepted Answer

reduce the axial velocity of the RF field

Answer

reduce the noise figure

Answer

ensure broadened operation

Answer

prevent the electron beam from spreading in the long tube

Question 8

a magic tee is nothing but a modification of

Accepted Answer

E ? plane

Answer

H - plane tee

Answer

two E - plane tees

Answer

A combination of E-plane and H-plen tee

Question 9

A cavity can be considered as

Accepted Answer

band pass filter

Answer

band stop filter

Answer

high pass filter

Answer

low pass filter