Question

While measuring internal resistance of cell a student finds null point at 72.0 cm with cell in circuit. He introduces resistance of 6 Ω from shunt resistance box. The balance point shifts to 60.0 cm. What will be internal resistance of cell?

• A. 1.5 Ω
• B. 1.2 Ω
• C. 1.3 Ω
• D. 1.4 Ω

Answer 1

Answer: (B)

1.2 Ω

Answer 2

r = $\left( \frac{72}{60} - 1 \right)$× 6 = $\frac{12 \times 6}{60}$ = 1.2 Ω