Calculating Current for .75T Solenoid (4300 turns, 38cm long)

[matt72lsu]

Homework Statement

You want to make a solenoid that is 38 cm long with 4300 turns. How much current should you run through the solenoid to produce a magnetic field of .75 T?

Homework Equations

B = uoNI

The Attempt at a Solution

I converted 38 cm to m (not sure where to use this number). i used the above equation but got it wrong. I have looked all in my textbook and can't find any other equation to use. help!

 

[rl.bhat]

In the equation N is the number of turns per unit length.

 

[matt72lsu]

so N x .38?

 

[rl.bhat]

so N x .38?

No. Nx0.38 = total number of turns.
N = 4300/0.38