Question

When the number of turns and the length of a solenoid both are doubled its self inductance becomes?

Answer 1

Answer:

it's self inductance becomes four times

good day

Answer 2

Solution :

It will become twice .

Explanation :

Self inductance is property of conductor by virtue of conductor opposes any change passing through .

Self inductance of solenoid:

$\green{\sf\:L=\dfrac{N^2\:u_{o}\:A}{l}}$

So According to the question if both length and no of turn will doubled , then

N ' = 2N

and l' = 2l

Then ,

$\sf\:L'=\dfrac{(2N)^2\:u_{o}\:A}{2l}$

$\sf\:L'=\dfrac{4N^2\:u_{o}\:A}{2l}$

$\sf\:L'=\dfrac{2N^2\:u_{o}\:A}{l}$

$\implies\sf\:L'=2L$

Hence , self inductance will increase two times.