Question

A pair of adjacent coils has a mutual inductance of 1.5 H. If thecurrent in one coil changes from 0 to 20 A in 0.5 s, what is thechange of flux linkage with the other coil?

Answer 1

Given: The mutual inductance of a pair of coils is 1.5 H, the initial current is 0 A and final current is 20 A and the time taken for the change in current is 0.5 s.

The induced emf is given as,

e= dϕ dt (1)

Where, the change in the flux linkage with the coil is dϕ.

The equation of emf in terms of mutual inductance is given as,

e=μ dI dt (2)

Where, the mutual inductance of a pair of coils is μ, the change in current is dI and the change in time is dt.

By substituting the value of e from equation (1) to equation (2), we get

dϕ dt =μ dI dt dϕ=μdI

By substituting the given values in the above expression, we get

dϕ=1.5×20 =30 Wb

Thus, the change in flux linkage is 30 Wb.