The expected answers were:
(a) (i) Selectivity, for a radio receiver, is a measure of the ability of the receiver to
distinguish between adjacent channels, and consequently tune to a desired
channel without attracting interference from the adjacent channels.
(ii) Sensitivity, measures the extent to which the receiver is able to pick and
process weak signals in the presence of background noise.
(b) Any three advantages
- Better selectivity
- Higher sensitivity
- Higher gain
- Better efficiency
(c) Any one advantage
- Higher costs
- More complex electronic circuitry.
This question was on communication systems, very few candidates attempted it.