A storage battery of emf 8.0 V and internal resistance 0.5 Ω is being charged by a 60 V dc supply using a series resistor of 12.5 Ω. The terminal potential difference between the terminals of the battery during charging is

10.0 V

The correct answer is Option (3) → 10.0 V

Given:

Battery emf: $E = 8 \, \text{V}$

Internal resistance: $r = 0.5 \, \Omega$

Series resistor: $R = 12.5 \, \Omega$

Supply voltage: $V_s = 60 \, \text{V}$

Current through circuit during charging:

$I = \frac{V_s - E}{R + r} = \frac{60 - 8}{12.5 + 0.5} = \frac{52}{13} = 4 \, \text{A}$

Terminal voltage of battery:

$V = E + I r = 8 + 4 \cdot 0.5 = 8 + 2 = 10 \, \text{V}$

Answer: Terminal potential difference $V = 10 \, \text{V}$