When the magnetic field is produced by two alternating currents or moving polarities interacting asynchronously, with opposite poles rotating with synchronous speed, around a central axis, a rotating magnetic field is produced. Static magnetic fields do not vary over time, and as such do not have a frequency (zero Hz).

In both electric motors and generators rotating magnetic fields are used .The interaction of magnetic fields in electric devices such as transformers is conceptualized and investigated as magnetic circuits. Magnetic forces give information about the charge carriers in a material through the Hall effect.

The rotating magnetic field is produced radially around the rotor by the varying currents in the stator windings. The rotating magnetic field induces eddy currents in the squirrel cage's vertical bars causing it to rotate. The rotation of the rotor and magnetic field are asynchronous.

The rotating magnetic field plays a key role in Industries, applications of rotating magnetic flux are like it is used in Electric motors, generators, and transformers

The main advantage of a rotating magnetic field is it requires less power comparatively, Less power means less sparking/losses across slip rings. Because the rotating field requires less power, it is possible to make the alternator completely brushless