A standard cell of 1.0185 V is used with a slide wire potentiometer. The balance was obtained at 60 cm. When an unknown emf was connected, the balance was obtained at 82 cm. The magnitude of unknown emf is

• 1.39 V
• 0.75 V
• 13.9 V
• 7.45 V

Correct Answer: 1.39 V

Explanation:

.