Which statement best describes magnetism?

• A. The energy stored in a magnetic field.
• B. The energy stored in an electric field.
• C. The force of attraction or repulsion between magnetic materials.
• D. The rate of change of current.

Answer: (C)

Magnetism is the force produced by magnetic fields that acts on magnetic materials and moving charges. The clearest way to describe it is the force of attraction or repulsion between magnetic materials, such as how magnets attract or push away each other or how a magnet pulls on iron. This observable interaction is the practical manifestation of magnetism.

The other statements refer to related ideas but not the basic phenomenon itself: energy stored in a magnetic field is a property of the field, not the definition of magnetism; energy stored in an electric field pertains to electricity; and the rate of change of current is tied to induced voltages from changing magnetic fields, which is a dynamic effect rather than the fundamental description of magnetism.