PHYSICS · Multi-part · CBSE · Physics · Magnetism and Matter · Magnetism and Matter
Problem
Two identical bar magnets, each 6 cm long, are placed on a horizontal surface so that their long axes lie along the same straight line. Their North poles face each other and are separated by a 1 cm air gap. Ignore friction with the surface.
(a) Draw a qualitative map of the magnetic field lines in the plane of the magnets, showing at least eight external lines and indicating the direction of each.
(b) Identify any point(s) in the plane midway between the two facing North poles where the net external magnetic field is approximately zero (a null point). Justify your answer by discussing vector addition of the individual fields from each magnet.
(c) A tiny paramagnetic bead is released from rest at the midpoint of the line joining the two North poles. Assuming gravitational effects are negligible, describe the subsequent motion of the bead and explain the forces responsible for that motion.
(d) Design an experiment using iron filings and a compass that would allow you to verify the existence and location of the null point predicted in part (b). Outline the procedure, the measurements or observations you would make, and the expected results that would confirm your prediction.