Question
Please answer correctly. An explanation would be ideal. Thank you. Must answer both for full points.
A single turn coil of radius 4.50 cm is held in a vertical plane and a magnet is rapidly moved relative to the coil as shown in the diagram below. The field inside the coil changes from 0.490 T to 0.365 T in 0.120 s. If the resistance of the coil is 4.30 Ohm, what are the magnitude and direction of the induced current in the coil as viewed from the size magnet? magnitude mA An emf is induced by rotating a 1047 turn, 20.0cm diameter coil in the Earth's 5.53 times 10 -5 T magnetic field. What average emf is induced, given the plane of the coil is originally perpendicular to the Earth's field and is rotated to be parallel to the field in 10.0ms?
Explanation / Answer
1) emf = dflux/dt = pi*4.5E-2^2*(0.49-0.365)/0.12=0.00663
I = V/R = 0.00663/4.3 = 0.00154 A = 1.54 mA
2) emf = dflux/dt = N A B/t = 1047*pi*.1^2*5.53E-5/10.0E-3=0.182 V