A cell has an open circuit voltage V1 and a closed circuit voltage V2 when...

JAMB 1980

A cell has an open circuit voltage V1 and a closed circuit voltage V2 when a current is flowing through it. Therefore, the internal resistance of the cell is

A. \(\frac{V_2}{I}\)
B. \(\frac{V_1}{I}\)
C. \(\frac{(V_1 + V_2)}{I}\)
D. \(\frac{(V_1 - V_2)}{I}\)
E. \(\frac{(V_2 - V_1)}{I}\)

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Correct Answer: Option D

Explanation

On open circuit, voltage = V\(_1\), On a closed circuit voltage drops due to internal resistance V\(_2\) = I r
But according to Ohm's law, voltage drop( V\(_d\) = I r

V\(_d\) = V\(_1\) - V\(_2\) = Ir

r = \(\frac{(V_1 - V_2)}{I}\)

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