Solving a problem in physics section 63 point 62 electr

62. The solenoid 160 cm length, the cross-sectional area of 19.6 cm2. The coil of the solenoid has 2000 turns, and it runs a current of 2 A. Find the average value of the emf induced in the coil, put the solenoid with an iron core, if the current in the solenoid is reduced to zero for 2 ms? Use graph B = f (H), shown in Fig.