344.  The phosphor type number used in tricolour picture tube is
A. P1
B. P4
C. P22
D. P31

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345. With reference to colour picture tubes, the shadow mask is used to
A. accomplish separation of the beam for red, green and blue colours
B. achieve colour convergence
C. allow generation of all natural colours from red, green and blue
D. correct certain distortions

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346. The widely talked about SONY TRINITRON concept for colour picture tubes uses
A. delta guns
B. in-line guns
C. a single electron three cathodes
D. a common electromagnetic all the three beams

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347. The equivalent resistance of an electron beam with a beam current of 1 mA at 20 kV will be
A. 20 N4S1
B. 10 MU
C. 40 Tvin
D. indeterminate from given data

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348. The automatic degaussing coil uses
A. alternating current at power line frequency
B. alternating current at horizontal scan frequency
C. alternating current at vertical scan frequency
D. a [er,amemt ,agmet

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349.  The cathode drive for the picture tube
A. requires a video signal with a positive sync polarity
B. requires a video signal with a negative sync polarity
C. is used to adjust the brightness level
D. is an essential requirement for negative transmission polarity

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350.  In a certain interlaced scanning pattern, the number of horizontal lines actually scanned per field (other than those blanked out) are 9j. If each vertical retrace is equivalent to 2 horizontal lines, the total number of horizontal lines per frame would be
A.23
B.19
C.21
D.

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