# Self Inductance of a Solenoid Problem

1. Apr 8, 2014

### liamporter1702

1. The problem statement, all variables and given/known data
Hi again guys, been stuck on this problem for a while now, thought it would be a simple bumping in some values in a given equation question but I can't get the correct answer Heres the problem:

What is the inductance of a 600 turn coil wound on a core of cross sectional area 450mm2 , length of 500mm and a relative permeability of 25?

2. Relevant equations
I assumed the equation I would use would be L=μ0μrn2Al
Where n = number of turns
A = cross sectional area
l = length
μ0 I took as 12.6x10^-7
and μr = 25

3. The attempt at a solution
When I put all these values into the equation I get 2.55, where as the given answer is 10mH. I'm stumped

2. Apr 8, 2014

### Andrev

The correct equation is: $$L=\frac{\mu_0 \mu_r n^2 A}{l}$$