Q. 154.3( 3 Votes )
The figure shows
1) When the rod is moved with a velocity v, there is a force acting on the rod due to a magnetic field which induces emf in the rod which is equal to e = Blv
From right-hand thumb rule, we can find out that the direction of emf is A to B as A is positive and B is negative.
2) There is no net force when K is open. This is because the magnetic force Fm = -e(v + B) is cancelled by the electric force
Fe = eE which is set up due to excess of charge of opposite sign at the ends of the rod( when the circuit was closed).
3) Zero. In this case, no emf is induced in the coil because the motion of the rod does not cut across the field lines.
Rate this question :