Which of the following is not luminous object?

Step 1: Analyze the question The question asks which object is not luminous. So we are looking for the one that does not produce its own light.

Step 2: Explain the concept

• A luminous object is one that produces (emits) its own light. Examples: the sun, stars, a burning candle, an electric bulb that is switched on.
• A non-luminous object does not produce its own light. We see it only because it reflects light from a luminous source. Examples: the moon, planets, mirrors, books, trees.

Step 3: Check each option

• A. The sun: It produces its own light through nuclear fusion, so it is luminous.
• B. The moon: It has no light of its own. It shines only by reflecting sunlight, so it is non-luminous.
• C. Lighted candle: The burning flame gives off its own light, so it is luminous.
• D. Star: Stars produce light by nuclear reactions, just like the sun, so they are luminous.

Step 4: Answer The moon is the only option that does not emit its own light.

Correct option: B

Tip: Remember "the moon only reflects". Planets and the moon are non-luminous, while the sun and stars are luminous. If the question says "not luminous", look for something that only reflects light.