Question

Which of the following is luminous object:
A.) Moon
B.) Planets
C.) Sun
D.) Earth

Answer 1

Hint: Non-luminous objects are objects which do not emit light by themselves but reflect light falling on them.

Complete step by step answer:

Luminous objects are objects which produce light of their own through various processes. Non-luminous objects are objects which do not emit light by themselves but reflect light falling on them. The stars are luminous objects which produce light through the process of nuclear fusion. Planets and satellites are non-luminous objects which do not produce light on their own but reflect the light falling so they appear bright in the sky.

So according to the question, the sun which is a star is a luminous object while the rest of the options are satellites and planets are all non-luminous objects.

So the answer for the question is option (C) –Sun.

Additional Information:

Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object.
In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical object.

Note: Most of the light emitted by luminous objects lies in the visible spectrum. Some objects can emit radiation at different ranges of the spectrum also.
Some living beings have the ability to produce light from their bodies through the process of natural luminescence, this occurs due to certain types of chemical reactions in the body.