The reading on a high resistance voltmeter. When a cell is connected across it is `2.2 V`. When the terminals of the cell are connected to a resistance of `5 Omega` the voltmeter reading drop to `1.8 V`. Find the internal resistance of the cell.

Answer

` (10)/(9) Omega`

Explanation

Here, `epsilon = 2.2 V, V = 1.8 V, R = 5 Omega , r = ?`
As `r = (( epsilon - V)/(V)) R = ((2.2 - 1.8))/(1.8) xx 5 = (10)/(5) Omega`