WBJEE · Physics · Current Electricity
Two identical cells each of emf \(\mathrm{E}\) and internal resistance \(\mathrm{r}\) are connected in parallel with an external resistance \(\mathrm{R}\). To get maximum power developed across \(R\), the value of \(R\) is
- A \(R=r / 2\)
- B \(\mathrm{R}=\mathrm{r}\)
- C \(R=r / 3\)
- D \(\mathrm{R}=2 \mathrm{r}\)
Answer & Solution
Correct Answer
(A) \(R=r / 2\)
Step-by-step Solution
Detailed explanation
\(R_{e q}=\frac{r}{2}\) \(I=\frac{2 E}{r+2 R}\) For max. power consumption. I should be max. So denominator should be min. for that \(r+2 R=(\sqrt{r}, \quad)\)
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