Question

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

1. what is the effect on the physical quantity indicated by ‘a’?
2. what is the effect on the physical quantity indicated as ‘b’?
3. give a reason for your answer in (b).

Answer 1

1. The physical quantity indicated by ‘a’ represents the induced emf or output voltage of the AC generator; therefore, when the speed of the generator is doubled, the output voltage also doubles.
2. The physical quantity indicated by ‘b’ represents the time period of the generator, so when the speed is doubled, the time period is halved.
3. When the speed at which the coil rotates in an AC generator is doubled, the output voltage frequency also doubles, and since the time period is the reciprocal of the frequency, it is halved.