1995 General Studies, all questions
UPSC Prelims 1995 · General Studies
Question 104: Science and Technology
The technique used to transmit audio signals in television broadcasts is
aAmplitude Modulation
bFrequency Modulation
cPulse Code Modulation
dTime Division Multiplexing
AnswerThe answer is (b).
In television broadcasting the picture signal is sent by amplitude modulation, with one sideband partly suppressed, while the sound signal is sent by frequency modulation. FM gives good sound quality with less noise and interference. Pulse code modulation and time division multiplexing are digital techniques used in telephony and data. Remember: TV picture AM, TV sound FM.
Why each option is right or wrong
- (a) Amplitude modulation is used for the picture signal, not the sound.
- (b) Right: frequency modulation.
- (c) Pulse code modulation is a digital method, not the analogue TV sound system of the time.
- (d) Time division multiplexing is a way of sharing a channel, not the audio modulation method.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1995, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.