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Q67 (CAPF/2019) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Geometrical optics Answer Verified

Which one of the following is NOT a luminous object?

Result
Your answer: —  Â·  Correct: D
Explanation

Luminous objects are defined as entities that emit their own light [2]. The Sun is a primary natural luminous source, producing light through nuclear reactions. Artificial sources like electric lamps and candles are also luminous; an electric lamp produces light via an incandescent filament [4], while a candle flame emits light through the combustion of gaseous substances [6]. In contrast, the Moon is a non-luminous object [3]. It does not generate its own light but becomes visible only because it reflects sunlight that falls upon its surface [6]. While the Moon appears bright in the night sky, it is technically an illuminated body rather than a source of light [3]. Therefore, among the given options, the Moon is the only object that does not emit its own light, making it non-luminous [2].

Sources

  1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 11: Light: Shadows and Reflections > Light: Shadows and Refl ections 11 > p. 154
  2. [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 11: Light: Shadows and Reflections > In a Nutshell > p. 165
  3. [4] Science-Class VII . NCERT(Revised ed 2025) > Chapter 3: Electricity: Circuits and their Components > Incandescent Lamp > p. 26
  4. [6] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Why do substances burn with or without a flame? > p. 70
  5. [3] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 11: Keeping Time with the Skies > 11.1.3 Making sense of our observations > p. 174
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