Question

When the number of turns in the two circular coils closely wound are doubled (in both), their mutual inductance becomes

• A. four times
• B. two times
• C. remains same
• D. sixteen times

Answer 1

Answer: (A)

four times

$M\propto N_1{N}_2$
so if both $N_1{N}_2$ are doubled,
$M^{\prime }=4M$