A flat coil of wire, having 5 turns, has an inductance L.The inductance of a similar coil having 20 turns is:
A)4L
B)L/4
C)16L
D)L/16
E)L

Question

Quizplus · Accepted Answer

Inductance of a coil is directly proportional to the square of the number of turns. Hence, in this case, the inductance of the coil with 20 turns will be (20/5)^2 times the inductance of the coil with 5 turns. Therefore, the inductance of the coil with 20 turns will be 16 times the inductance of the coil with 5 turns, which is option C).

A Flat Coil of Wire, Having 5 Turns, Has an Inductance