By what factor is the self-inductance of an air solenoid changed if only its number of coil turns,N,is tripled?
A) 1/3
B) 3
C) 6
D) 9
E) 1/9

Question

By what factor is the self-inductance of an air solenoid changed if only its number of coil turns,N,is tripled?
A) 1/3
B) 3
C) 6
D) 9
E) ​1/9

Quizplus · Accepted Answer

The self-inductance of an air solenoid is directly proportional to the square of its number of turns. Therefore, if the number of coil turns is tripled (N → 3N), the self-inductance will increase by a factor of (3N)^2/N^2 = 9.

By What Factor Is the Self-Inductance of an Air Solenoid