Two cells of emf 2 V and 4 V and internal resistance of 0.5 Ω each are connected with an external resistor of resistance 3 Ω as shown in the figure. The terminal potential difference of 2 V cell is:

2.25 V

The correct answer is Option (1) → 2.25 V

Two cells of emf $2 \, \text{V}$ and $4 \, \text{V}$, each with internal resistance $0.5 \, \Omega$, are connected in series with external resistance $3 \, \Omega$.

They are connected in opposite direction (4 V opposes 2 V):

Net emf: $E = 4 - 2 = 2 \, \text{V}$

Total resistance: $R_\text{total} = 3 + 0.5 + 0.5 = 4 \, \Omega$

Current: $I = \frac{E}{R_\text{total}} = \frac{2}{4} = 0.5 \, \text{A}$

For 2 V cell (which is being charged):

Terminal potential difference = $E_1 + I r_1 = 2 + (0.5)(0.5) = 2.25 \, \text{V}$

Terminal potential difference of 2 V cell = $2.25 \, \text{V}$