A 2.64m -long coil containing 225 loops is wound on an iron core (average \mu = 1850\mu _0) along with a second coil of 115 loops. The loops of each coil have a radius of 2.10cm . If the current in the first coil drops uniformly from 11.0A to zero in 91.0ms.
Part(a) Determine the mutual inductance {\rm M}.
Part(b) Determine the emf induced in the second coil.