Question

A 26 turn circular coil of wire has diameter 0.97 m. It is placed with its axis along the direction of the Earth's magnetic field of 57.0 µT, and then in 0.207 s it is flipped 180°. An average emf of what magnitude is generated in the coil?
______mV

Answer 1

N = 26

D = 0.97 m

R = 0.485 m

B = 57 μT   = 57 * 10 ^ -6 T

dt = 0.207 s

Average induced emf E = N A [ B cos 0 - B cos 180] / dt

                                     = 2NBA / dt

where A = area of the loop = π R ^ 2

                                           =0.738 m ^ 2

So, E = 10.58 mV                                    

Thanks have a nice day