Question

Chapter 22 - Electromagnetic Induction 4-A flat circular coil with N = 105 turns, a radius of r = 4 × 10-2 m, and a resistance of R 0.480 ? is exposed to an external magnetic field that is directed perpendicular to the plane of the coil. The magnitude of the external magnetic field is changing at a rate of AB = 0.783 T s, thereby inducing a current in the coil. Find the magnitude of the magnetic field at the center of t ?? coil that is produced by the induced current.

Answer 1

No of turns N = 105 radius r = 4 times 10^- 2m Area A = pir^2 = (3.1415)(4 times 10^- 2)^2 = 5.0265 times 10^- 3 m^2 Resistance R = 0.48 ohm Delta B/Delta t = 0.783 T/s Induced emf E = NA Delta B/Delta t E = (105)(5.0265 times 10^- 3)(0.783) = 0.41325 volt Induced Current I = E/R I = 0.41325/0.48 = 0.8609A b) Magnitude of magnetic field B = M_0 NI/2R = (4pi times 10^- 7)(105)(0.8609)/2(0.48) = 1.183 times 10^- 4 T