Online Questions and Answers Topic Outline
- MCQs in Basic Principles of Microwave Communications
- MCQs in Electro-Optics
- MCQs in Photonics
- MCQs in Optoelectronics
- MCQs in Electromagnetics
- MCQs in Avionics, Aerospace, Navigational and Military Applications
- MCQs in Medical Electronics
- MCQs in Cybernetics
- MCQs in Biometrics
MCQs in Microwave Communications and Principles Series
Following is the list of multiple choice questions in this brand new series:
Continue Practice Exam Test Questions Part VIII of the Series
351. What are limits of microwaves?
- a) 1 – 25,000 GHz
- b) 1 – 50,000 GHz
- c) 1 – 75,000 GHz
- d) 1 – 100,000 GHz
352. The following transmission lines are used for microwave frequencies, except:
- a) waveguide
- b) twin lead
- c) coax
- d) stripline
353. How much must a waveguide be?
- a) over a half-wave
- b) over a quarterwave
- c) over a wavelength
- d) over three-fourths of a wavelength
354. How high must a waveguide be?
- a) over a wavelength
- b) over a quarter wave
- c) over a half wave
- d) over two wavelengths
355. What is the designation of the lowest-frequency microwave band?
- a) V band
- b) X band
- c) Ku band
- d) L band
356. What is the designation of the highest-frequency microwave band?
- a) R band
- b) Ka band
- c) V band
- d) L band
357. What is reduced by using choke flanges?
- a) refraction
- b) reflection
- c) absorption
- d) cancellation
358. What is the name of the microwave transmission line that is used in printed circuits?
- a) microstrip
- b) coax
- c) twin lead
- d) twisted pair
359. Where is the resistive load placed in a directional coupler?
- a) front end of the primary
- b) front end of the secondary
- c) back end of the primary
- d) back end of the secondary
360. One of the following is a type of bolometer
- a) calorimeter
- b) thermocouple
- c) barreter
- d) carreter
361. Why are bolometers not used to detect modulation?
- a) thermal sluggishness
- b) inefficiency
- c) less accurate
- d) less precise
362. The advantage of a resonant cavity over a hairpin tank?
- a) lesser Q
- b) wider bandwidth
- c) higher Q
- d) efficiency
363. What type of coupling is used between a waveguide and a waveguide wavemeter?
- a) loop antenna
- b) quarterwave antenna
- c) hole
- d) E probe
364. Which microwave tube has a repeller?
- a) TWT
- b) Klystron
- c) Magnetron
- d) BWO
365. Which microwave tube has a series of cavities?
- a) magnetron
- b) klystron
- c) TWT
- d) BWO
366. Which microwave tube has a helix
- a) klystron
- b) magnetron
- c) multicavity klystron
- d) BWO
367. Which microwave tube has a horseshoe magnet?
- a) magnetron
- b) klystron
- c) TWT
- d) BWA
368. What is the advantage of a gridless klystron
- a) power input
- b) gain
- c) attenuator
- d) power output
369. Which vacuum tube do you think oscillate at the highest frequency
- a) Magnetron
- b) Gunn
- c) Klystron
- d) BWO
370. How would a balun be used to change 200 ohms to 50 ohms?
- a) use a higher turns ratio
- b) use a higher frequency
- c) reverse it
- d) use low frequency
371. How could a balun change 100 ohms to 900 ohms
- a) use 3:1 turns ratio
- b) use 1:3 turns ratio
- c) use 9:1 turns ratio
- d) use 1:9 turns ratio
372. How high a frequency can transistor generate?
- a) above 10 GHz
- b) above 5 GHz
- c) above 2 GHz
- d) above 7.8 GHz
373. What is the microwave application of a varactor?
- a) mixer
- b) frequency multiplier
- c) demodulator
- d) demultiplexer
374. What diode does better than varactor in microwave frequencies?
- a) step recovery
- b) tunnel
- c) PIN
- d) Gunn
375. The following diodes can generate microwave AC except:
- a) Tunnel
- b) LSA
- c) IMPATT
- d) Magnetron
376. For what are PIN diodes used in microwave?
- a) mixers
- b) modulators
- c) oscillators
- d) amplifier
377. What is the other name for LSA diodes?
- a) negative resistance
- b) bulk-effect
- c) tunneling effect
- d) time-space
378. What is the advantage of LSA over a Gunn Diode?
- a) more efficient
- b) higher power
- c) less noise
- d) higher frequency
379. What is wrong with the term Gunn Diode?
- a) not a gun
- b) not a semiconductor
- c) not a diode
- d) should be spelled with single “n”
380. What is important property do ferrites have which is used as a switch?
- a) faraday rotation
- b) resonance absorption
- c) magnetic properties
- d) high curie temperature
381. Which is used in circulators?
- a) resonance absorption
- b) magnetic properties
- c) ion resonance
- d) faraday rotation
382. What is the advantage of using a circulator with two transmitter and two receivers?
- a) many antennas
- b) less interference
- c) easy coupling
- d) one antenna only
383. To what must the fourth port be connected in a tunnel diode amplifier?
- a) resistor
- b) inductor
- c) capacitor
- d) impedance
384. To what must the third port be connected in a multiplexer circulator
- a) reflecting short circuit
- b) absorbing short circuit
- c) reflecting open circuit
- d) absorbing open circuit
385. What does radar mean?
- a) radio detection and range
- b) radio direction and radiation
- c) radio direction and range
- d) range direction radiation
386. In what distance unit are marine radars calibrated?
- a) statute miles
- b) kilometers
- c) nautical miles
- d) feet
387. What time unit is the equivalent of a radar mile?
- a) 12.3 microseconds
- b) 6.8 microseconds
- c) 4.5 microseconds
- d) 7.1 microseconds
388. In what frequency band does marine radar operate?
- a) 9.5 GHz S band
- b) 3 GHz X band
- c) 9.5 GHz Ku band
- d) 3 GHz S band
389. To what two circuits would a radar timer circuit feed signals?
- a) modulator and mixer
- b) amplifier and circulator
- c) modulator and circulator
- d) amplifier and modulator
390. What is the target display on a CRT called?
- a) crosshair
- b) blip
- c) center spot
- d) round
391. What is the main bang on a PPI radar set?
- a) blip
- b) center spot
- c) bearing
- d) round
392. What is the ability to separate adjacent equidistant targets called?
- a) bearing resolution
- b) narrow bandwidth
- c) high frequency
- d) shorter wavelength
393. What is the approximate rotational rate of a radar antenna?
- a) 20 rpm
- b) 5 rpm
- c) 25 rpm
- d) 10 rpm
394. How is radar CRTs differ from TV?
- a) square
- b) round
- c) rectangular
- d) trapezoidal
395. What circuits make up the radar transmitter?
- a) multivibrator
- b) trapezoidal oscillator
- c) sine wave generator
- d) blocking oscillator
396. What type of oscillator determines the PRR?
- a) blocking
- b) pulse
- c) square
- d) blocking or pulse
397. What other circuit might be used as an oscillator that determines the PRR?
- a) trapezoidal generator
- b) unbalanced multivibrator
- c) bistable multivibrator
- d) sinewave generator
398. Why are hydrogen-gas thyratrons used in radar?
- a) fast-ionize
- b) cheaper
- c) accurate
- d) efficient
399. What is the other name for a pulse-forming network in radars?
- a) tuned circuit
- b) oscillators
- c) delay line
- d) capacitive circuits
400. What determines the PRR in odd-time radar sets?
- a) tuned circuit frequency
- b) oscillator frequency
- c) spark gap speed
- d) MOPA transmitter time
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