Question

The self inductance of a long solenoid cannot be increased by

• A. Increasing its area of cross section
• B. Increasing its length
• C. Increasing the current through it
• D. Increasing the number of turns in it

Answer 1

Answer: (C)

Increasing the current through it

Answer 2

The self inductance of a long solenoid is given by

$L = \frac{\mu_{0}N^{2}A}{l}$

Where

N = number of turns

L = Length

A = Cross sectional area

From the above expression it is clear that the self inductance of a long solenoid does not depend upon the current flowing through it.