Q. A square coil of side 25 cm having 1000 turns is rotated with a uniform speed in a magnetic field about an axis perpendicular to the direction of the field. At an instant t, the emf induced in the coil is e =200sin 100$\pi t$. The magnetic induction is
A) 0.50 T
B) 0.02 T
C) $10^{- 3}\ T$
D) 0.01 T
Explanation
(d) $e = 200\sin{100\ \pi t}$
We have,
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ e_{0} = 200,$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \omega = 100\ \pi$
$\therefore\ \ \ \ \ \ \ \ \ \ \ \ \ \ BAN\omega = e_{0}$
$\therefore\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ B = \frac{e_{0}}{AN\omega}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \frac{200}{(0.25 \times 0.25) \times 1000 \times 100\pi}$
Or $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ B = 0.01\ T$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.