**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 :confused: Heres the problem:

What is the inductance of a 600 turn coil wound on a core of cross sectional area 450mm^{2} , length of 500mm and a relative permeability of 25?

**2. Relevant equations**

I assumed the equation I would use would be L=μ_{0}μ_{r}n^{2}Al

Where n = number of turns

A = cross sectional area

l = length

μ_{0} I took as 12.6×10^-7

and μ_{r} = 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 :confused:

http://ift.tt/PKChTz