A wire is being wound around a rotating wooden cylinder of radius R. One end of the wire is connected to the axis of the cylinder, as shown in the figure. The cylinder is placed in a uniform magnetic field of magnitude B parallel to its axis and rotates at N revolutions per second. What is the potential difference between the open ends of the wire?
A. 0
B. 2πNBR
C. πNBR2
D. BR2/N
E. πNBR3
(GR9677 #47)
Faraday's Law: ɛ = − dΦ/dt
with Φ = NBA
Given:
N revolution per second
B uniform (constant)
A constant
ɛ = − BA dN/dt
= − BπR2N
|ɛ| = πNBR2
Answer: C
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