A battery is charged at a potential of `15 V` for `8` hours when the current flowing is `10 A`. The battery on discharge supplies a current of `5 A` for `15` hours. The terminal voltage during discharge is `14 V`. The 'Watt-hour" efficiency of the battery is.

Options

A. `82.5 %`
B. `80 %`
C. `90 %`
D. `87.5 %`

Answer

D

Explanation

`eta = (14 xx 5 xx 15)/(15 xx 10 xx 8) xx 100 = 87.5 %`.