According to Cowling's theorem, it is impossible to have a system of this type that is self-sustaining and axisymmetric.
According to Cowling's theorem, it is impossible to have a system of this type that is self-sustaining and axisymmetric. The fast subtype have growth- rates that are independent of resistivity, and can operate even in the limit of perfect conductivity. The omega effect can act in systems with differential rotation to generate toroidal fields from poloidal fields. Systems of this type require a seed field, and become self-sustaining above the critical magnetic Reynolds number. A magnetic field generates a current which induces a reinforcing magnetic field in this sort of system, thought to explain the magnetic fields of most stars and the Earth. For ten points, what system shares its name for the device created by Faraday to create an electric current from mechanical force?
According to Cowling's theorem, it is impossible to have a system of this type that is self-sustaining and axisymmetric.
Dynamo