Q. A metal of radius 100 cm is rotated at a constant angular speed of 60 $rads^{- 1}$ in a plane at right angles to an external field of magnetic induction 0.05 ${Wbm}^{- 2}$. The emf induced between between the centre and a point on the rim will be
A) 3 V
B) 1.5 V
C) 6 V
D) 9 V
Explanation
(b) The emf developed between the centre and the rim is
$e = \frac{1}{2}B\omega l^{2} = \frac{1}{2} \times 0.05 \times 60\lbrack 1\rbrack^{2} = 1.5\ V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.