386. In case of cathode drive for colour picture tube CRT, the signals needed in PAL standards are
A. (R?Y), (B?Y) and (G?Y)
B. Y, U and V
C. R, G and B
D. Y, I and Q

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387. One of the following causes excessive snow in the picture
A. Excessive antenna signal
B. Weak RF amplifier
C. Weak video amplifier
D. Defective AGC circuit

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388. In reverse AGC,
A. as the received signal strength increases, the gain is reduced by driving the transistors from active region towards cut-off
B. as the received signal strength increases, the gain is reduced by driving the transistor from active region towards saturation
C. the amplifier circuits that have to receive the AGC bias must use PNP transistors
D. the amplifier circuits that have to receive the AGC bias must use NPN transistors

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389. The volume control in a TV receiver is located
A. at the input of sound IF amplifier
B. at the input of audio pre-amplifier
C. at the input of audio output stage
D. at the input of loudspeaker

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390. In forward AGC,
A. the amplifier circuits whose gain is to be controlled by AGC bias must use NPN transistors
B. the amplifier circuits whose gain is to be controlled by AGC bias must use PNP transistors
C. asttenaceided signalgmngth incneases, the gain of the am ptifipr stages is reduced by driving the taansistors try aids saturation
D. as the mazeivecl si3rialgotragth inotaases, the gain of the amplifier stages is reduced by driving the tonaistprs tnw a-wig cut-off

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391. When (R-Y) and luminance signals are combined, the result is
A. Red video
B. Green video
C. Blue video
D. no signal

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392. One of the following equipments is used for testing of chrominance section
A. Vectoroscope
B. Sweep generator
C. Oscilloscope
D. Waveform monitor

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