The expected answers were:
(a) Compatibility with respect to colour T.V.
This refers to ability of the black and white TV set to receive colour TV signals.
(b) Any of the two secondary colours
(i) Cyan
(ii) Magenta
(iii) Yellow
(c) (i) Brightness
The intensity of illumination of a TV picture.
(ii) Contrast
This is the difference in intensity between the black and white parts of the reproduced TV picture.
(iii) Aspect ratio
This is the ratio of the width to height of the picture frame.
The question was on Communication System. It was not popular with the candidates. The performance of the candidates was not encouraging.