Question #657d6

1 Answer
Oct 27, 2015

The magnetic field is given by the curl of the vector potential, A.

B=\nabla\times A

Explanation:

The vector potential , A , is used because it often provides an easier way to find B.

It is analogous to how the electric field, E, can be derived from the scalar potential V. \quad \quad\quadE=\nabla V

A can be calculated by:

A=\mu_0/{4\pi}\intJ_{(r)}/{r-r_0}dV

where J is the current density at the point r. This expression comes from the Helmholtz Theorem.