Top 150+ Solved Radiation and Microwave Techniques MCQ Questions Answer
Q. The primary purpose of the helix in a traveling-wave tube is to
a. prevent the electron beam from spreading in the long tube
b. reduce the axial velocity of the rf field
c. ensure broadband operationreduce the noise figure
d. none ofthe above.
Q. The TWT is sometimes preferred to the magnetron as a radar transmitter outputtube because it is
a. capable of a longer duty cycle
b. a more efficient bandwidth
c. more broadband
d. less noisy
Q. A magnetron whose oscillating frequency is electronically adjustable over a widerange is called a
a. coaxial magnetron
b. dither-tuned magnetron
c. frequency agile magnetron
d. vtm
Q. A disadvantage of microstrip compared with strip line is that micro strip
a. does not readily lend itself to printed circuit techniques
b. is more likely to radiate
c. is bulkier
d. is more expensive and complex to manufacture
Q. For best low-level noise performance in the X-band, an amplifier should use
a. a bipolar transistor
b. a gunn diode
c. a step-recovery diode
d. an impatt diode
Q. Considering a coaxial transmission line, maximum voltage on the line divided bythe minimum voltage equals the
a. characteristic impedance
b. iswr
c. vswr
d. inductive reactance
Q. Which of the following is used to measure SWR?
a. multimeter
b. spectrum analyzer
c. reflectometer
d. oscilloscope
Q. Reflections on a transmission line can occur when
a. impedance of the source and load are matched
b. impedance of the source and the load are mismatched
c. resonance conditions are obtained
d. power transfer between source and load is maximum
Q. A measure of the mismatched between line and load impedance is called as
a. reflection coefficient
b. standing wave ratio
c. loss
d. standing waves
Q. Power density is basically termed as power per unit are
a. reflected
b. radiated
c. diffracted
d. refracted
Q. Parabolic and lens antennas are extensively used for
a. short waves
b. micro waves
c. medium frequency waves
d. all of the above
Q. The television receiver antennas are usually
a. parabolic dish type
b. helical antennas
c. dipoles
d. none of the above
Q. Lens antennas used for microwaves are usually made of
a. paraboloid surfaces
b. polystyrene
c. dielectric media having large refractive index
d. glass of low refractive index