College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 25

An aluminum ring of radius 5.00 cm and resistance 3.00 × 10 4 V is placed around the top of a long aircore solenoid with 1 000 turns per meter and a smaller radius of 3.00 cm, as in Figure P20.64. If the current in the solenoid is increasing at a constant rate of 270 A/s, what is the induced current in the ring Assume the magnetic field produced by the solenoid over the area at the end of the solenoid is one-half as strong as the field at the center of the solenoid. Assume also the solenoid produces a negligible field outside its crosssectional area.