InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
The potential difference in open circuit for a cell is 2.2 votls . When a `4 ohm`resistor is connected between its two electrodes that potential difference becomes 2 volts. The internal resistance of cell will beA. `1 ohm`B. `0.2 ohm`C. `2.5 ohm`D. `0.4 ohm` |
|
Answer» Correct Answer - D (d) The potential difference in open circuit for the cell is 2.2 volt, it mens the emf of the battery should be 2.2 volts. Now a `4 ohm` resistor is connected between its two electrodes, then the potential difference across the battery becomes 2 volts `V = epsilon - ir implies 2 = 2.2 - ir` `implies ir = 0.2 V` But `i= (epsilon)/(r + R) = (2.2)/(r + 4)` Putting the value of `i` in (i), we get `r =0.4 ohm`. |
|