A coil has 600 turns which produces 5×10−3 Wb/turn of flux when 3 A current flows in the wire. This produced 6×10−3 Wb/turn in 1000 turns secondary coil. When the switch is opened, the current drops to zero in 0.2 s in primary. Find
a. mutual inductance,
b. the induced emf in the secondary,
c. the self-inductance of the primary coil.