Question

Five cells each of emf E and internal resistance \(r\) send the same amount of current through an external resistance R whether the cells are connected in parallel or in series. Then the ratio \( \left( \frac{R}{r} \right) \) is

• A. 2
• B. \(\frac{1}{2}\)
• C. \(\frac{1}{5}\)
• D. 1
• E. 5

Hint:

For \(n\) identical cells, the current delivered to an external resistor \(R\) is the same in series and parallel combinations if and only if \(R = r\).

Answer 1

The Correct Option is D