337. A high f-number is used
A. when the scene has high light level
B. when the scene has low light level
C. when the dept-offield improvement is not the consideration
D. none of these

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338. With reference to camera pick up tubes,the image lag problem isseverest in
A. plumbicon tubes
B. saticon tubes
C. vidicon tubes
D. newicon tubes

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339. With referenc to television camera pick up tube, the f-number is changed by
A. changing the lens focal lengt
B. changing the lens aperture using an iris
C. changing the lens itself
D. using multiple lenses

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340. The part of visible spectrum where the camera pick up tubes have the greates output is
A. infra red
B. green
C. red
D. yellow-green

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341.  Beam alignment magnets for the camera tube are adjusted by rocking back and forth one of the following controls
A. Electrical focus
B. Optical focus
C. Beam current
D. none of these

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342. The diagonal screen size in inches of a television picture tube type number 19CP22 is
A.19
B.22
C. indeterminate from given data
D. none of these

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343.  The phosphor type number used in monochrome picture tubes is
A. P1
B. P4
C. P22
D. P31

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