Solenoidal Field

a vector field that has no source. In other words, the divergence of a vector a of a solenoidal field is equal to zero: div a = 0. An example of a solenoidal field is a magnetic field: div B = 0, where B is the magnetic induction vector. A solenoidal field can always be represented in the form a = curl b; here, curl is the differential operator also known as rotation, and the vector b is called the vector potential of the field. (See alsoVECTOR CALCULUS.)