# NEET Questions Solved

PMT - 2004

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 mean terminal voltage during discharge is 14 V. The "Watt-hour" efficiency of the battery is

(1) 82.5%

(2) 80 %

(3) 90%

(4) 87.5%

(4) Watt hour efficiency $=\frac{\text{Discharging\hspace{0.17em}\hspace{0.17em}energy}}{\text{Charging\hspace{0.17em}\hspace{0.17em}energy}}$

$=\frac{14×5×15}{15×8×10}=0.875=87.5%$

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