What is B = (mu * l)/(2pi*r) used for?

[alice emily]

Homework Statement

what is this equation used for

Homework Equations

B=(mu*l)/(2*pI*r)

The Attempt at a Solution

 

[pimpalicous]

It's ampere's law applied to a straight wire. (I think you can also derive it from Biot savart)

Its used to find the magnetic field due to a straight wire w/current.

Picture a bunch of circles, each one centered on the wire. The equation says that the magnetic field is the same at any point on the same circle. Also, the farther the cirlce is, the weaker the magnetic field and the stronger the current, the stronger the magnetic field.

 

[Doc Al]

Read all about it: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html#c2"