2006 General Studies, all questions
UPSC Prelims 2006 · General Studies
Question 86: Science and Technology
What does the term ‘Dolby B’, or ‘Dolby C’ printed on tape recorders and other sound systems refer to?
aFrequency modulated system
bAmplitude Modulated system
cNoise reduction circuit
dBoth DC and AC power can be used
AnswerThe answer is (c).
Dolby B and Dolby C are noise-reduction systems used in cassette tape recorders and other sound equipment to reduce tape hiss. Dolby B is the simpler and more widespread system; Dolby C gives about twice the reduction. They are not modulation systems, and they do not concern the power supply.
Why each option is right or wrong
- (a) Not a frequency modulation system.
- (b) Not an amplitude modulation system.
- (c) Correct: Dolby B and C are noise-reduction circuits.
- (d) Not about AC or DC power.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2006, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.