(i) Define mutual inductance.
(ii) 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 0.5s, what is the change of flux linkage with the other coil ?

Explanation

### Step-by-Step Solution

**(i) Definition of Mutual Inductance:**

Mutual inductance (M) is defined as the ability of one coil to induce an electromotive force (EMF) in another coil due to a change in current in the first coil. Mathematically, it can be expressed as:

\[
M = \frac{\Phi_s}{I_p}
...