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An electric motor runs on a d.c. source ...

An electric motor runs on a d.c. source of emf `epsilon` and internal resistance r. show that the power output of the source is maximum when the current drawn by the motor is `epsilon//2r`.

A

`(E)/(r)`

B

`(E)/(2r)`

C

`infty`

D

0

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The correct Answer is:
b
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