Question

Statement I The self-induced emf is also called the back emf.
Statement II The self-induced emf opposes any change in the current in a circuit.

• A. Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I.
• B. Both Statement I and Statement II are correct but Statement II is not the correct explanation of Statement I.
• C. Statement I is correct but Statement II is incorrect.
• D. Statement I is incorrect but Statement II is correct.

Answer 1

Answer: (B)

The self-induced emf is also called the back emf as it opposes any change in the current in a circuit. Physically, the self-inductance plays the role of inertia. It is the electromagnetic analogue of mass in mechanics. So, work needs to be done against the back emf $(\epsilon )$ in establishing the current. This work done is stored as magnetic potential energy.