Q. A square loop of side $22\ cm$ is converted into circular loop in $0.4s$. A uniform magnetic field of $0.2\ T$ directed normal to the loop then the $emf$ induced in the loop is
A) $6.6 \times 10^{- 3}\ V$
B) $6.6 \times 10^{- 5}\ V$
C) $4.6 \times 10^{- 4}\ V$
D) $4.60 \times 10^{- 8}\ V$
Explanation
(a) $e = \frac{d\phi}{dt} = \frac{BdA}{dt} = \frac{2(\pi r^{2} - L^{2})}{dt} = 6.6 \times 10^{- 3}\ V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.