Physics

Physics

Problem

![](https://storage.googleapis.com/diraq-contents/question-bank/question-images/1372d89cc58c/2025_11_20_9ad509d56b7bf2a0d815g-09.jpg) 1983E2. The series circuit shown above contains a resistance R=2×106\mathrm{R}=2 \times 10^{6} ohms, a capacitor of unknown capacitance C , and a battery of unknown emf E\mathcal{E} and negligible internal resistance. Initially the capacitor is uncharged and the switch S is open. At time t=0\mathrm{t}=0 the switch S is closed. For t>0\mathrm{t}>0 the current in the circuit is described by the equation: i(t)=ioe−t/6\mathrm{i}(\mathrm{t})=\mathrm{i}_{\mathrm{o}} \mathrm{e}^{-\mathrm{t} / 6} where io=10\mathrm{i}_{\mathrm{o}}=10 microamperes and t is in seconds. a. Determine the emf of the battery. b. By evaluating an appropriate integral, develop an expression for the charge on the right-hand plate of the capacitor as a function of time for t>0\mathrm{t}>0. ![](https://storage.googleapis.com/diraq-contents/question-bank/question-images/ad86e74418e2/2025_11_20_9ad509d56b7bf2a0d815g-09.jpg) c. On the axes below sketch a graph of the charge QQ on the capacitor as a function of time tt. d. Determine the capacitance C.

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