Calculate the magnetic flux density

[moenste]

Keep in mind that L is the length of the wire in the coil (because you need the resistance R of the wire). L is not the length of the cylinder on which the wire is wound. If you had to make a coil of N turns by winding wire around a cylinder of radius r, what length of wire would you need?

L = N 2 π r?

B = Q N 2 π r u / π r² N = Q 2 u / r that gets B = 0.2 T. Thank you!

 

[TSny]

L = N 2 π r?

B = Q N 2 π r u / π r² N = Q 2 u / r that gets B = 0.2 T. Thank you!

Yes, that's it.