Which statement best defines magnetism?

• A. A force of attraction or repulsion produced by magnets or moving charges.
• B. Energy carried by sound waves produced by vibrating objects.
• C. The energy stored in a compressed spring.
• D. The rate at which heat is transferred through a material.

Answer: (A)

Magnetism is the force of attraction or repulsion produced by magnets or moving charges. This force comes from magnetic fields created by moving electric charges and by magnetic materials, causing interactions with other magnets or charges. Permanent magnets have north and south poles, attracting opposite poles and repelling like poles. The other ideas describe sound energy, elastic potential energy, and heat transfer, none of which are magnetic forces. So the statement that defines magnetism best captures how magnetic forces arise and act.