The potential difference across the terminals of a battery is 10 V when there is a current of 3A in the battery from the negative to the positive terminal. When the current is 2A in the reverse direction, the potential difference becomes 15 V. The internal resistance of the battery is

Explanation

`E-3r=10" ………(i)"`
`E+2r=15" ……….(ii)"`
Solving these two equations, we get, `r=1Omega`