IIT JEE , AIEEE Forum - Physics , Magnetism

master_purav

Always remember that emf is produced only when the conductor cuts the magnetic field lines.

Now when a rod moves in a magnetic field, the electrons and protons experience a force coz they are also moving with the rod. Any charge moving in a magnetic field experiences a force of magnetic origin.

for inducing magnetic field, the conductor must travel in a plane that is perpendicular to the magnetic field.

This can be veified by the fact that F = q(v x B).

Only electron will move in the direction of force coz protons are fixed at their positions.

Thus only if v is perp. to B the force is exerted on electrons. (Even if its not perpendicular only the perpendicular component will exert a force)

This can be verified from the expression that

induced emf = B (l x v)

Thus l must also be perpendicular to velocity. Even if its not, only the perp. component will affect it.

So, Also the direction of travel must be perpendicular to the length of rod.

Hence we get the required direction

In short, the rod must cut the magnetic field lines.....

Ask & Discuss Questions with Community & Experts