A coil of 800 turns and 50 cm^2 area makes 10 rps about an axis in its own plane in a magnetic field of 100 gauss…

Q: A coil of 800 turns and 50 cm^2 area makes 10 rps about an axis in its own plane in a magnetic field of 100 gauss perpendicular to this axis. What is the instantaneous induced emf in the coil?

Sol: A = 50 cm2 = 50 × 10-4 m2

N = 10 rps , N = 800

B = 100 gauss = 100 × 10-4 T = 10-2 T

Now, e = e0 sin ωt = NBAω sin ωt

e = 800 × 10-2 × 50 × 10-4 × 2π × 10 sin(20πt)

or ,  e = 2.5 sin (20πt) volts.