A capacitor C is connected to a battery circuit having two switches S₁ and S₂ and resistors R₁ and R₂. The capacitor will be fully charged when

When both are open no charge will pass through the capacitor.

When S₁ is open and S₂ is closed capacitor is not connected to the battery so not charge will flow.

When both S₁ and S₂ are closed, the potential drop across the capacitor will be $\frac{{\mathrm{ER}}_2}{{\mathrm{R}}_1+{\mathrm{R}}_2}$ where E is the EMF of cell.

When S₁ is closed and S₂ is open, the potential drop only occurs across the capacitor so the potential drop across the plates of the capacitor will be E.

The capacitor will be fully charged when S₁ is closed and S₂ is open.