Question

When the resistance of $2\Omega$ is connected across the terminal of the cell, the current is 0.5 amp. When the resistance is increased to $5\Omega$, the current is 0.25 amp. The emf of the cell is

• A. 1.0 volt
• B. 1.5 volt
• C. 2.0 volt
• D. 2.5 volt

Answer 1

The correct option is B 1.5 volt

By using $E=\frac{i_1{i}_2}{(i_2-i_1)}(R_1-R_2)=\frac{0.5\times 0.25}{(0.25-0.5)}(2-5)=1.5$ volt