Question

A square current carrying loop is changed to a circular loop in time \( t_1 \). Then

• A. emf is induced in loop for time \( t<t_1 \)
• B. emf is induced in loop for time \( t>t_1 \)
• C. no emf is induced in loop during whole process
• D. emf is induced due to change in magnetic field

Hint:

Changing the geometry of a current-carrying loop changes the magnetic flux, inducing emf in the process.

Answer 1

The Correct Option is A

Step 1: Changing the Shape of the Loop.
When a current carrying loop changes shape, it causes a change in magnetic flux. This changing flux induces an emf according to Faraday’s law.
Step 2: Induced emf Duration.
The induced emf lasts during the process of shape change, from the square loop to the circular loop. Therefore, emf is induced in the loop for time \( t<t_1 \).
Step 3: Conclusion.
The correct answer is (A), emf is induced in loop for time \( t<t_1 \).