Page 3 - LN

A moving charge in a magnetic field (direction of motion not parallel to the field

direction) experiences a force called Lorentz force. Since current is due to flow of
charge, therefore a conductor carrying current will experience a force.

The force acting on a current-carrying conductor placed in a magnetic field is: F=BIl
Now, if a charge Q flows in time t then the current I = . So, writing in

place of I in the above equation, we get:
Suppose the particle carrying the charge Q travels a length l in time t.
Then the velocity v of the charged particle will be equal to . Writing v in
place of in the above equation, we get:

Force on moving charge, F = B x Q x v
Where B = Magnitude of magnetic field, Q = Charge on the moving particle
and v = Velocity of the charged particle (in metre per second). In vector

notation
When an electric current is passed through a conductor, a magnetic field is produced
around the conductor. Faraday thought that as a
magnetic field is produced by electric current, it should be possible to

produce an electric current by the magnetic field. According to him,
whenever there is a change in the magnetic lines of force associated with a

conductor, an electromotive force (e.m.f.) is set up at the ends of the
conductor which lasts as long as the change is taking place. This
phenomenon is called electromagnetic induction.