In physics, the production of an
electromotive force (emf) in a circuit by a
change of magnetic flux through the circuit.
The emf so produced is known as an induced
emf, and any current that may result is known
as an induced current. The phenomenon is
applied in the induction coil. If the change
of magnetic flux is due to a variation in the
current flowing in the same circuit, the
phenomenon is known as self-induction; if it
is due to a change of current flowing in
another circuit it is known as mutual
induction.