Question

During charging of a cell, how does terminal voltage (V) compare to EMF (ε)?

Options

• V = ε/2

• V = ε

• V > ε

• V < ε

Answer 1

During charging, the external source must provide a voltage greater than the EMF to push current into the cell against its natural potential difference. Using \[V = ε + Ir\], the terminal voltage exceeds the EMF by the amount \[Ir\], which is the extra voltage needed to overcome internal resistance.