A diamagnetic substance is a material that creates an opposing magnetic field when exposed to an external magnetic field. This means that diamagnetic substances are repelled by magnets. Here's why:
1. Nature of Diamagnetism: Diamagnetic materials have no unpaired electrons, and their atomic moments generally cancel out. When placed in a magnetic field, they develop an induced magnetic moment that opposes the applied field.
2. Response to Magnetic Poles: Due to their opposition to the applied magnetic field, diamagnetic substances are repelled by both the north and south poles of a magnet. This is because they tend to move from stronger to weaker parts of the magnetic field.
3. Experimental Observation: When a diamagnetic substance is brought near a bar magnet, it experiences a force that pushes it away from both poles.
Considering the behavior of diamagnetic materials, the correct answer is: "repelled by north pole as well as by south pole".