Q. A wheel with ten metallic spokes each $0.50\ m$ long is rotated with a speed of $120\ rev/min$ in a plane normal to the earth’s magnetic field at the place. If the magnitude of the field is 0.4 gauss, the induced e.m.f. between the axle and the rim of the wheel is equal to
A) $1.256 \times 10^{- 3}V$
B) $6.28 \times 10^{- 4}V$
C) $1.256 \times 10^{- 4}V$
D) $6.28 \times 10^{- 5}V$
Explanation
(d) $e = Bl^{2}\pi v = 0.4 \times 10^{- 4} \times (0.5)^{2} \times (3.14) \times \frac{120}{60}$
$= 6.28 \times 10^{- 5}V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.