The friends are ready to try a problem. A battery has an emf of 12.0 V and an internal resistance of 0.05 Ω. Its terminals are connected to a load resistance of 1.1 Ω. Find the terminal voltage of the battery. V Calculate the power delivered to the load resistor, the power delivered to the internal resistance of the battery, and the power delivered by the battery. PR = W Or = W Delivered by battery = W

Terminal voltage = 11.5 V

Power across load = 119.7 W

Power across internal resistance = 5.4 W

Power delivered by battery = 125.2 W

Explanation:

The current in the circuit is given by

where E is the emf of the battery, R us the load resistance and r is the internal resistance.

The terminal voltage is the potential difference across the load resistor.

V = I × R = 10.43 A × 1.1 Ω = 11.5 V

The power across any resistance is given by

For the load resistor,

For the internal resistance,

The power delivered by the battery is

This could also be found by

The discrepancy in both answers is due to the approximations. The second answer is better.