JAMB - Physics (2024 - No. 108)
An accumulator is 90% efficient. If it gives out 2700J of energy while discharging, how much energy does it take in?
3600J
3000J
3200J
2430J
Explication
Efficiency = \(\frac{\text{ Output energy}}{\text{input energy}}\) x 100
Efficiency = 90% = 0.9, Output energy = 2700J
Input energy = \(\frac{2700}{0.9}\) = 3000J