A coil of wire is comprised of 5 turns, has a current of 2 mA running through it, and a net magnetic field at its center of B is equal to start fraction mu naught over 40 end fraction times T. What is the radius of the coil of wire?

20cm

Explanation:

A coil wire comprises of 5 turns, it has a current of 2mA

A net magnetic field at the center of B is equal to Mu over 40 end fractions times T

The radius of a coil of wire with N turns is r = 0.28 m. A clockwise current of Icoil = 1.0 A flows in the coil,

Therefore 40/2mA = 20