Question

Which of the following is a non luminous object?

• A. Candle flame
• B. Sun
• C. Earth
• D. Fire fly

Answer 1

The correct option is C Earth

Objects are classified into two types, based on the tendency to produce light. They are:
1. Luminous object
2. Non luminous object

Luminous object : Objects that can emit light energy by themselves are known as luminous objects.
Examples : Sun, stars, candle, electric bulb etc.

Non luminous object: Objects that cannot emit light energy by themselves are known as non-luminous objects. They are visible because they reflect the light of luminous objects.
Examples : Earth, moon, cloth, coal, book etc

Here candles, fire and sun can emit light energy by themselves so they are luminous objects. While the Earth does not have its own light but reflects the light which falls on it. Hence, it is a non luminous object.