Which statement describes a luminous object?

Which statement describes a luminous object?

• A. It emits its own light.
• B. It only reflects light from other sources.
• C. It blocks light completely.
• D. It changes color when heated.

Answer: (A)

Being luminous means an object makes its own light. When something emits light, it can be seen in the dark without needing light from another source—like a sun, a light bulb, or a firefly. The statement describes that an object produces its own light, which is exactly what luminous means. The other ideas describe different things: an object that only reflects light from elsewhere isn’t emitting light itself, so it isn’t luminous. Blocking light completely describes an opaque barrier, which doesn’t say anything about light production. Changing color when heated refers to how temperature affects glow, but it isn’t the general definition of a luminous object.

Being luminous means an object makes its own light. When something emits light, it can be seen in the dark without needing light from another source—like a sun, a light bulb, or a firefly. The statement describes that an object produces its own light, which is exactly what luminous means.

The other ideas describe different things: an object that only reflects light from elsewhere isn’t emitting light itself, so it isn’t luminous. Blocking light completely describes an opaque barrier, which doesn’t say anything about light production. Changing color when heated refers to how temperature affects glow, but it isn’t the general definition of a luminous object.