Question

A cell of internal resistance 2 ohms supplies current to a 6 ohms resistor. What is the efficiency of the cell?. ​

Answer 1

75% is the efficiency of the cell.

Explanation:

Internal resistance is the resistance generated due to the devices present in the circuit. Most preferably, it is the resistance of the battery connected to the circuit.

As the current, resistance of the resistor and the internal resistance of the battery is given as 6 A, 6 ohms and 2 ohms.

Then the efficiency of the cell is $E = \frac{IR}{I (R+r)} =\frac{R}{r+R}$

So, the efficiency of the cell is $E=\frac{R}{r+R}$

Then, E = $\frac{6}{2+6}=\frac{6}{8}$

So, the efficiency is 75%.

75% is the efficiency of the cell.