A battery is charged at a potential fo 15 V for 8 h when the current folwing is 10A. The battery on discharge supplies a current of 5A fo 15h . The mean terminal voltage during discharge is 14V. The watt-hour efficiency of the battery is

Options

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

Answer

D

Explanation

`eta = ("Discharging energy")/("Charging energy") xx 100`
`= (14 xx 5 xx 15)/(15 xx 10 xx 8) = 87.5%`