Question

A rectangular loop of sides 10 cm × 20 cm is kept outside a region of uniform magnetic field |B| = 5 mT as shown in the figure. The loop is moved with the velocity of 5 cm/s till it goes completely out of the magnetic field.

A rod PQ of resistance R lies across frictionless conducting rails in a constant uniform magnetic field B, as shown in the figure. Assuming that the rails have negligible resistance, the force required to pull the rod to the right at constant velocity v is:

The figure shows a rectangular conductor PQRS in which the arm PQ of length 10 cm and resistance 0.4 Ω is free to move. It is kept in a uniform magnetic field B = 0.2 T acting perpendicular into the plane of PQRS. If arm PQ is moved with a velocity v of 5 cm/s as shown, find : (a) the current induced in the loop, and (b) the power required to move the arm. (Resistances of arms PS, SR and RQ are negligible.)

A rectangular conductor MNPQ with a movable arm MN (resistance r) is kept in a uniform magnetic field as shown in the figure. Resistance of arms MQ, QP and PN are negligible. Obtain the expression for the : (a) current induced in the loop specifying its direction, and (b) power required to move the arm.