Question

A large circular coil of radius R and a small circular coil of radius r are put in vicinity of each other. If coefficient of mutual inductance of this pair equals 1 mH, what would be the flux linked with larger coil when a current of 0.5 A flows through the smaller coil? When would current in the smaller coil falls to zero, what would be its effect in the larger coil ?

Answer 1

Here, `M = 1 mH = 10^(-3) H, phi = ?`
`I = 0.5 A, phi = MI = 10^(-3) xx 0.5 = 5 xx 10^(-4) Wb`
When current in smaller coil falls to zero, an e.m.f. is induced in larger coil due to mutual induction.