50. Second time around echoes are caused bY
A. second time reflection from target
B. echoes returning from targets beyond the cathode ray tube range
C. echoes that arrive after transmission of the next pulse
D. extreme ends of bandwidth

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51. Which of the following diode is used as detector in a radar?
A. gunn diode
B. schottky diode
C. IMPATTdiode
D. any of the above

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52. In a radar in case the return echo arrives after the allocated pulse interval, then
A. it will not be received
B. the receiver will get overloaded
C. it may interfere with the operation of the transmitter
D. the target will appear closer than it really is

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53. The average power of a pulsed radar transmitter is given by
A. the product of peak power of the pulse and the duty cycle
B. peak power divided by the number of pulses repeated in one second
C. peak power divided by the duty cycle
D. none of the above

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54. PPI in a radar system stands for
A. plan position indicator
B. pulse position indicator
C. plan position image
D. prior position indentification

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55. In case the ratio of the antenna diameter to the wavelength in a radar system is high, this is likely not to result in
A. increased capture area
B. good target discrimination
C. difficult target acquistion
D. largermaximum range

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56. The term RADAR stands for
A. radio direction and reflection
B. radio detection and ranging
C. radiowaves despatching and receiving
D. random detection and reradiation

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