Chapter 7, Problem 1AC

Which of the following is luminous?

a. Moon

b. Mars

c. Sun

d. All of the above

To determine

The luminous body from the following options.

Moon

Mars

Sun

All of the above

Answer to Problem 1AC

Solution:

Option (c) is correct.

Explanation of Solution

Introduction:

A body is said to be a luminous body if it emits or radiate light on its own. They produce their own light from their own source of energy. Example: Sun is a luminous body.

Explanation:

Reason for the correct option:

Since the sun produces its own light by the help of nuclear fusion reactions which converts hydrogen to helium with a liberation of enormous amount of energy and light. This makes sun a luminous body.

Hence, option (c) is correct.

Reason for the incorrect options:

Option (a) is incorrect becausemoon takes light from the sun and reflects it and is visible to us. It doesn’t produce light of its own. So it is not luminous. Hence, it is a wrong answer.

Option (b) is incorrect because Mars also takes light from sun and reflects. So it is non-luminous. Hence, it is a wrong answer.

Option (d) is incorrect because option (c) is correct. So it can’t be the answer.

Hence, options (a), (b) and (d) are incorrect.

Conclusion:

Among the given options, only Sun is luminous.