# Formula Magnetic field of a current-carrying ring Electric current    Radius

## Magnetic field

Unit
Magnetic field (B-field) generated by an annular, current-carrying conductor loop (ring) along the $$z$$ axis. The ring is perpendicular to the $$z$$ axis, with the $$z$$ axis passing through the center of the ring.

## Electric current

Unit
Current flowing through the ring. A larger current produces a larger magnetic field.

Magnetic field constant is a physical constant and occurs whenever electromagnetic fields are involved. It has the value: $$\mu_0 ~=~ 4\pi \cdot 10^{-7} \, \frac{ \mathrm{N} }{ \mathrm{A}^2 }$$