GEOLOGY

Detailed explanation-1: -The two ends of the bar magnet exert the maximum magnetic force. It is equally strong at the north pole and the south pole. The force exerted by the middle of the magnet is weaker.

Detailed explanation-2: -It is strongest at the poles. So, what are magnetic poles? Magnetic poles are opposite ends of a magnet where the magnetic field is strongest.

Detailed explanation-3: -Detailed Solution. The correct answer is zero. Magnetism at the centre of Bar magnet is zero.

Detailed explanation-4: -Lines of force are three-dimensional, surrounding a bar magnet on all sides and it is crowded at pole and parallel in middle making magnetic field weaker in middle.