Question
Eddy currents are produced when
A.
a metal is kept in varying magnetic field
B.
a metal is kept in steady magnetic field
C.
a circular coil is placed in a magnetic field
D.
current is passed through a circular coil
Answer :
a metal is kept in varying magnetic field
Solution :
Eddy currents are the currents induced in the body of a conductor when the amount of magnetic flux linked with the conductor changes.
e.g. when we move a metal plate out of a magnetic field, the relative motion of the field and the conductor again induces a current in the conductor for which conduction electrons move in closed loops forming circular eddy currents in such a way that it opposes the magnetic field that created it as if the electrons are caught in an eddy or whirlpool. It is also called Foucault current.