A 5.50 cm diameter wire coil is initially oriented so that its plane is perpendicular to a magnetic field of 0.690 T pointing up. During the course of 0.170 s, the field is changed to one of 0.240 T pointing down. What is the average induced emf in the coil?
The area of an adjustable single loop is reduced from 1.0m^2 to .25m^2 in 0.1s. The magnetic field of 2.0T is perpendicular to the plane of the loop. What is the average induced emf?