Solenoid Magnetic Field wire spacing Help

[pat666]

Homework Statement

You have 12m of 0.50mm diameter copper wire and a power supply capable of passing 17A through the wire.
What magnetic field strength would you obtain inside a 2.0cm diameter solenoid with the wire spaced as closely as possible?

Homework Equations

B=u₀nI

The Attempt at a Solution

I found the number of loops by
D=.002+2*1*10^-3m (diametre plus 2 radi of wire)?
then n=12/circumfrence =173.6turns (C=pi*D
then I subbed all the values and got 0.0037T which is wrong
all help appreciated - I think my problem is in calculating the number of turns??

 

[6Stang7]

The diameter of the wire will effect the pitch (loop density) of the coil, but not the total number of loops. I take it you have the answer to the problem?

 

[pat666]

Hey, its for an online mastering physics test - - - - using D as .02m I get .00408T but I didnt use the radius at all so I think it may be wrong?