1. | \(20\) | 2. | \(30\) |
3. | \(40\) | 4. | \(10\) |
Two cells having the same emf, are connected in series through an external resistance R. Cells have internal resistance r1 and r2 respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is:
1.
2.
3.
4.