A battery is charging with an EMF of 12 V, internal resistance of 20 Ω, and current of 0.1 A. What is the terminal potential difference?

14 V

10 V

12 V

None of these

Terminal potential difference (V) during charging is given by $V = E + Ir$ , where $E$ is EMF, $I$ is current, and $r$ is internal resistance.

Substituting values:

V = 12 + (0.1 times 20) = 12 + 2 = 14 , text{V}.