Top 150+ Solved Radiation and Microwave Techniques MCQ Questions Answer
Q. The dominant mode in a rectangular waveguide is TE10 because this mode has
a. no attenuation
b. no cut off
c. no magnetic field component
d. the highest cut off wavelength
Q. The phase velocity for the TE10 mode in an air filled rectangular waveguide is
a. less than c
b. greater than c
c. equal to c
d. none of the above
Q. The phase velocity of an electrometric wave propagating in a hollow metallicrectangular waveguide in the TE10 mode is
a. equal to its group velocity
b. less than velocity of light in free space
c. equal to velocity of light in free space
d. greater than velocity of light in free space
Q. . Consider an air filled rectangular waveguide with a cross – section of5 cm × 3 cm.For this waveguide, the cut off frequency (in MHz) of TE21mode is
a. 7.81 ghz
b. 9.01 ghz
c. 11.2 ghz
d. 6.89 ghz
Q. The cut off frequency of waveguide depends upon
a. the dimensions of the waveguide.
b. the dielectric property of the medium in the waveguide.
c. the characteristic impedance of the waveguide
d. the transverse and axial components of the fields
Q. When an electromagnetic waves are propagated in a waveguide
a. they travel along a broader walls of the guide
b. they are reflected from the walls but do not travel along them
c. they travel through the dielectric without touching the walls
d. they travel along all four walls of the waveguide
Q. Which of the following waveguides tuning components is not easily adjustable?
a. screw
b. stub
c. iris
d. plunger
Q. A directional coupler with three or more holes is sometimes used in preference tothe two-hole couple
a. because it is more efficient
b. to increase coupling of signal
c. to reduce spurious mode generation
d. to increase the bandwidth of the system
Q. A ferrite is
a. a nonconductive with magnetic properties
b. an intermetallic compound with particularly good conductivity
c. an insulator which heavily attenuates magnetic fields
d. a microwave semiconductor invented by faraday
Q. A PIN diode is
a. a metal semiconductor point-contact diode
b. a microwave mixer diode
c. suitable for use as a microwave switch
d. often used as a microwave detector
Q. A microwave tube amplifier uses an axial magnetic field and a radial electric field.This is the
a. reflex klystron
b. coaxial magnetron
c. travelling wave magnetron
d. cfa
Q. Indicate the false statement. Transit time in microwave tubes will be reduced if
a. the electrodes are brought closer together
b. a higher anode current is used
c. multiple or coaxial leads are used
d. the anode voltage is made larger
Q. The multicavity klystron
a. is not a good low-level amplifier because of noise
b. has a higher repeller voltage to ensure a rapid transit time
c. is not suitable for pulsed operation
d. needs a long transit time through the buncher cavity to ensure current modulation
Q. The cavity magnetron uses strapping to
a. prevent mode jumping
b. prevent cathode back heating
c. ensure bunching
d. improve the phase focusing effect