In a coil of self inductance of 5 henry, the rate of change of current is 2 ampere per second, the e.m.f. induced in the coil is
The mutual inductance between two coils is 1.25 henry. If the current in the primary coil changes at a rate of 80 ampere/second, then the induced e.m.f. in the secondary coil is
In a transformer, the coefficient of mutual inductance between the primary and the secondary coil is 0.2 henry. When the current changes by 5 ampere/second in the primary coil, the induced e.m.f. in the secondary coil will be