Question
Physics Question on Electromagnetic induction
A copper disc of radius 0.1 m rotates about an axis passing through its center and perpendicular to its plane with 10 revolutions per second in a uniform transverse magnetic field of 0.1 T. The emf induced across the radius of the disc is:
A
π/10 V
B
2π/10 V
C
10 π mV
D
20 π mV
Answer
10 π mV
Explanation
Solution
The correct option is: (C): 10 π mV.
The electromotive force (emf) induced between the center and rim of a rotating disc can be expressed as:
E = 1/2 * B * ω * R^2
Substituting the given values:
E = 1/2 * 0.1 * 2π * 10 * (0.1)^2
E = 10π * 10^-3 volt