Question

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

• A. 80%
• B. 87.5%
• C. 85%
• D. 82.5%

Hint:

The watt-hour efficiency of a battery is a measure of how effectively the energy stored during charging is used during discharge.

Answer 1

The Correct Option is C

The watt-hour efficiency is calculated by comparing the energy supplied by the battery during discharge to the energy stored during charging. The efficiency can be expressed as: \[ \text{Efficiency} = \frac{\text{Energy Discharged}}{\text{Energy Charged}} \times 100 \]