The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.8 m. The magnetic field of the generator is 0.21 T, and the coil rotates at an angular speed of 26 rad/s. What is the peak emf of this generator?

Answer in V

1 answer

Use the information on wire length and radius to get the number of turns, N.

5.8 meters = 2*pi*R*N
N = 7.7 Let's call it 7 turns. The other 0.7 m might be used for connections.

Maximum Flux = Phi = N*B*A
= 7*0.21*pi*R^2
= 0.067 Webers

Peak EMF = w*Phi= 1.7 volts
where w is the angular velocity of the coil.