1. A conductor, when placed at right angles to a magnetic field of density 700 mT, experiences a force of 20 mN, when carrying a current of 200 mA. Calculate the effective length of the conductor.
2. A conductor, 0.4 m long, lies between two pole pieces, with its length parallel to the pole faces. Determine the force exerted on the conductor, if it carries a current of 30 A, and the flux density is 0.25 T.