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Question
In a potentiometer, a cell is balanced against 110 cm when the circuit is open. A cell is balanced at 100 cm when short-circuited through a resistance of 10 Ω. Find the internal resistance of the cell.
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Solution
r = `R (I_1/I_2 -1)`
= `10 (110/100 -1)`
= 1 Ω
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