The potential difference across the terminals of a battery is `8.4 V` when there is a current of `1.50 A` in the battery from the negative to the positive terminal. When the current is `3.50 Air`, the reverse direction, the potential difference becomes `9.4 V`.
(a) What is the internal resistance of the battery?
(b) What is the emf of the battery?

Answer

A, B

Explanation

`8.4=E-1.5r`
`9.4=E+3.5r`
Solving these two equations we get
`r=0.2Omega` and `E=8.7V`