The potential difference across terminals of a battry is `9.0 V`, when a current of `3.5A` flows through it from its negative terminal to the positive terminal .When a current of `2A` flows through in the opposite direction, the terminal potential difference is `12V`. Find the internal resistance and emf of the battery

Answer

`2 Omega, 16 V`

Explanation

When current flow through the battery from its the negative to positive terminal (i.e , current is draw from battery ) then
`V = epsilon - 1 r or 9.0 = epsilon - 3.5 r `…..(i) When current flow through the battrey from its the positive negative to terminal (i.e , battery is charged) then
`V = epsilon 1 r or 12 = epsilon - 2 r `…..(ii)
On solving (i) and (ii) we get
`r = 2 Omega and epsilon = 16 V`