Question

In a potentiometer experiment, the balancing length with a cell is 560cm. When an external resistance of I0 ohms is connected in parallel to the cell the balancing length changes by 41cm. The internal resistance of the cell in ohm is

• A. 0.8
• B. 2.4
• C. 1.2
• D. 0.6

Answer 1

The correct option is A 0.8

We Know,

$\begin{array}{c}r=R\left(\frac{l_1}{i_2}-1\right)\\ =10\left(\frac{560}{519}-1\right)\\ =0.78\cong 0.8\end{array}$

Hence, Option $A$ is correct.