Question

Need help with this question (#3). Please help

turn coil has a diameter of 10 cm. The coil is placed in a spatially uniform magnetic field of magnitude 0.50 T so that the face of the coil and the magnetic field are perpendicular. Find the magnitude of the emf induced in the coil it magnetic field is reduced to zero uniformly in (a) 0.10 s, (b) 1.0 s, and (c) 30.0 s

Answer 1

Given No. of turnor N = 60 diameter d = 10 times 10^-2 m d = 10^-1 m = 0.1m radius r = d/2 = 0.05 m Area A = pi r^2 = pi(0.05m)^2 A = 0.007853 m^2 B = 0.50T a0 at dt = 0.10s E = -d phi/dt = -NA dB/dt = -NA(B_f - Bi)/dt tan B_f = 0 E = NA Bi/dt = 60 times (0.007853m)^2 (0.50T)/0.105 E = 2.356 V b) dt = 1.05 E = NA Bi/dt = 60(0.007853 m^3) (0.507)/(1.05) E = 0.2356 v c) dt = 30.05 E = NA Bi/dt = 60(0.007853m^2) (0.50 T)/(30.0S) E = 7.853 times 10^-3 T E = 7.853 mT