Question

when number of turns in a coil is tripled, without any change in the length of coil, its self inductance becomes

Answer 1

L = inductance is proportional to the number of turns per unit length.

B = μ₀ n i
Emf = - dФ/dt = - d (B*A)/ dt = - L di/dt
     L = μ₀ n A


So self inductance becomes  three times.

Answer 2

Answer:

9 times

Explanation:

Self-inductance of a solenoid =(μAx^{2})​/L

So, self-induction proportional to n^{2}

So, induction becomes 9 times when n is tripled.