Question

How does the mutual inductance of a pair of coils change when,

(i) distance between the coils is increased and

(ii) number of turns in the coils is increased?

Solution

Using the formula,

$straight ϕ space equals space MI space$
i) Mutual inductance decreases when the distance between the coils is increased.

ii) Now using the formula,

$straight M subscript 21 space equals space straight mu subscript straight o space straight n subscript 1 space straight n subscript 2 space straight A space straight l$
On increasing the number of turns in the coil, mutual inductance also increases.