Question

A generator is designed to produce a maximum emf of 150 V while rotating with an angular speed of 3900 rpm . Each coil of the generator has an area of 1.9×10−2 m2.If the magnetic field used in the generator has a magnitude of 4.9×10−2 T , how many turns of wire are needed?

Answer 1

Maximum emf E = 150 V

Angular speed w = 3900 rpm

                           = 3900 * 2(pi) rad / 60 s

                           = 408.2 rad / s

Area   A= 1.9 * 10^-2 m²

Magnetic field B = 4.9 * 10^-2 T

We know E = B*A*N*w

so, No.of truns N = E / ( BA w )

N = 150/4.9*10^-2*1.9*10^-2*408.2

N = 394.70 395