Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is

As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an e.m.f. $$V$$ volt is induced in the loop. The work done (joule) in taking a charge Q coulomb once along the loop is

The magnetic flux through a circuit of resistance R changes by an amount $$\Delta $$$$\phi $$ in a time $$\Delta $$t. Then the total quantity of electric charge Q that passes any point in the circuit during the time $$\Delta $$t is represented by

For a coil having L = 2 mH, current flow through it is $$I = {t^2}{e^{ - t}}$$ then, the time at which emf become zero