Question

When the number of turns in a solenoid are doubled without any change in the length of the solenoid, its self inductance becomes

• A. Half
• B. Double
• C. Four times
• D. Eight times

Answer 1

The correct option is C Four times

Self inductance of solenoid L=$\frac{\mu N^{2}A}{l}$

Where n is number of turns

L is directly proportional to $N^2$

If N is doubled , L is increased by 4 times