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

Ans:

Given,

Mutual inductance µ = 1.5H

Current at initial point is given by I1= 0 A

Current at final point is given by I2  = 20 A

Therefore, change in current becomes

dI = I1- I2 =  = 20 – 0 = 20 A

Time taken for the change is given by t = 0.5s

We know that the expression for induced emf is –

$e=\frac{d\phi }{dt}$

Where, Phi represents the change in Induced flux

Now, the relation between the emf and inductance is given by –

\[e=\mu \frac{dI}{dt}\]

Upon equating both the above equations, we get –

\[\frac{d\phi }{dt}=\mu \frac{dI}{dt}\]

\[\frac{d\phi }{dt}=1.5\times 20=30Wb\]

Therefore, the change in flux linkage is 30 Wb.