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Question
A cell of emf ‘E’ and internal resistance ‘r’ is connected across a variable resistor ‘R’. Plot a graph showing the variation of terminal potential ‘V’ with resistance R. Predict from the graph the condition under which ‘V’ becomes equal to ‘E’.
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Solution
V becomes equal to E when no current flows through the circuit.
The condition under which V will be equal to E is when R = ∞
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