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

Answer 1

Answer: (A)

emf is induced in loop for time $t<t_1$

For the time $t<t_1$, area of loop changes. Hence, magnetic flux linked with it changes during this time and emf is induced thereby.