In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across `60 cm` of the potentiometer wire. If the cell is shunted by a resistance of `6 Omega`, the balance is obtained across `50 cm` of the wire. The internal resistance of the cell is

Options

A. `0.5 Omega`
B. `0.6 Omega`
C. `1.2 Omega`
D. `1.5 Omega`

Answer

C

Explanation

(c ) `r = ((l_(1) - l_(2)))/(l_(2)) xx R' = ((60 - 50)/(50)) xx 6 = 1.2 Omega`