Physics
The given diagram shows the output of an AC generator. If the speed of the generator coil is doubled, then:

(a) what is the effect on the physical quantity indicated by ‘a’?
(b) what is the effect on the physical quantity indicated as ‘b’?
(c) give reason for your answer in (b).
Electro-Magnetism
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Answer
(a) As, the physical quantity indicated by 'a' is induced emf or output voltage of the a.c. generator so on doubling the speed of the generator, the output voltage also gets doubled.
(b) As, the physical quantity indicated by 'b' is time period of the generator so on doubling the speed, the period becomes half.
(c) When in an a.c generator the speed at which the coil rotates is doubled the frequency of output voltage is also doubled and since time period is reciprocal of the frequency so it gets halved.
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