AP EAMCET · PHYSICS · Current Electricity
A battery with a \(12 \mathrm{~V}\) emf has an initial charge of \(80 \mathrm{~A} . h\). If the potential across the terminals stays constant until battery is completely discharged, then this battery can deliver energy at the rate of \(120 \mathrm{~W}\) for a time
- A \(16 \mathrm{~h}\)
- B \(8 \mathrm{~h}\)
- C \(4 \mathrm{~h}\)
- D \(5 \mathrm{~h}\)
Answer & Solution
Correct Answer
(B) \(8 \mathrm{~h}\)
Step-by-step Solution
Detailed explanation
We have, \(\begin{aligned} \Delta \mathrm{U} & =\mathrm{P} \Delta \mathrm{t}=\mathrm{q} \varepsilon \\ \Delta \mathrm{t} & =\frac{\mathrm{q} \varepsilon}{\mathrm{P}}=\frac{(80 \mathrm{~A} . \mathrm{h}) \times(12 \mathrm{~V})}{120 \mathrm{~W}}=8 \mathrm{~h}\end{aligned}\)
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