A cell has emf of 2.2 V, when connected to a resistance of `5 Omega`, the potential difference between the terminals of the cell becomes 2.1 V, the internal resistance for the cell is

Options

A. `0.12 Omega`
B. `0.48 Omega`
C. `0.24 Omega`
D. `0.50 Omega`

Answer

C

Explanation

`E=2.2 V, R=5 Omega, V=2.1 V`,
`E=lR+ir implies (E-V)/(V)R=r`
`(2.2-2.1)/(2.1)xx5=r implies (0.1)/(2.1)xx5=r`
`r=0.24 Omega`