How Many Turns of Wire Are Needed for a Solenoid with These Specifications?

[ahazen]

How many turns of wire would be on a solenoid carrying a current 4.9 A if the solenoid is 17 cm in diameter, 248 cm long, and the field at the center is 2.9 × 10-3 T?

I can't seem to get the right answer...

I plug the values into B=n*u0*I and then solve for N.
I know that n=N/length

 

[collinsmark]

Hello ahazen,

What answer are you getting? (You need to show your work. )

 

[ahazen]

I plug in: 2.9e-3=n(4*pi*10^-7)(4.9)
and then solve for n.
Then i divide by the length.

I keep getting something like 1899, 1.899, 18.99 depending on how i write the length (248, or .248, or .0248).

 

[ahazen]

Thank you for your help:) I figured it out.:) I took B*L=N u0*I and solve for N to get 1168 turns.