# Self inductance of a solenoid

1. Oct 12, 2004

### Monsu

hey,
i was just confused here, which is the right formula for finding the self inductance of a solenoid, given the number of turns, the cross-sectional area, the length, and the current.

is it L = Uo x Ur x N^2 x A / L
(Uo = mu o, Ur = mu r)??

pls if it is wrong, let me know the right formula.
thanks!
Monsurat.

Last edited: Oct 12, 2004
2. Oct 12, 2004

### maverick280857

I think...it is $$L = \mu n^2 LA$$ where n = number of turns per unit length = N/L. Yours is correct.