A rectangular loop of sides 8 cm and 2 cm with a cut is stationary between the pole pieces of an electromagnet. The magnetic field of the magnet is normal to the loop. The current feeding the electromagnet is reduced so that the field decreases from its initial value of 0.3 T at the rate of `0.02 T s^-1`. If the cut is joined and the loop has a resistance of `1.6 Omega` , how much power is dissipated by the loop as heat? What is the source of this power?