Question

A cell of electric motive force 2 volts supplies a current of 0.8 ampere through a cell of resistance 2 ohms . calculate the internal resistance of the cell

Answer 1

Solution

Given data are

EMF of cell(E) =2V

Resistance (R) =2$\Omega$

Current (I) =0.8 A

So potential difference

V= IR=$0.8\times2=1.6V$

Internal resistance of cell is given by $r=\frac{E-V}{I}=\frac{2-1.6}{0.8}=0.5\Omega$

Therefore internal resistance of cell is 0.5$\Omega.$