351. During the scanning process, the signal that ensures that the electron beam does not scan the same horizontal line again and again in a given frame, is
A. horizontal scan signal
B. vertical scan signal
C. horizontal blanking signal
D. sync signal

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352. With reference to the sawtooth waveform used for linear scanning, horizontal or vertical,
A. the complete cycle includes both the trace and the retrace
B. the beam moves faster during trace than during retrace
C. the linear rise is for flyback
D. the sharp fall in amplitude produces trace

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353. If the horizontal flyback is 20 precent, this time equals (assume FCC standards)
A. 12.7 us
B. 64 us
C. 63.5 us
D. none of these

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354.  In interlaced scanning, there is a one-half line spacing between the start positions for scanning odd and even fields. This is done to produce
A. exact interlacing
B. line pairing
C. linear scanning
D. equal number of lines in odd-line and even-line interlaces

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355. While the sawtooth waveforms are used as scanning signals, the sync pulses are needed to get
A. proper timing
B. scanning linearity
C. exact interlace pattern
D. rid of keystoning effect

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356.  The three parts of a composite video signal for one horizontal line are
A. the camera signal, the horizontal sync and the horizontal blanking
B. the camera signal, the horizontal blanking and the equalising pulses
C. the camera signal, the carrier and the horizontal sync
D. the camera signal, the carrier and the horizontal blanking with superimposed horizontal sync

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357. The average DC level of the video signal, if close to the blanking level, represents
A. a light scene
B. a dark scene
C. a scene with high contrast
D. a scene with low contrast

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