Q. The period of one revolution of Sun around the centre of Galaxy is called

Explanation by: Mr. Dubey

A cosmic year (also called a galactic year) is the time it takes for the Sun to complete one full orbit around the center of the Milky Way galaxy.

This period is estimated to be about 225–250 million Earth years.


Other Options Explained:

(A) Parsec → A unit of distance in astronomy, equal to 3.26 light-years.

(B) Astronomical year → The time Earth takes to complete one orbit around the Sun (365.25 days).

(D) Light year → The distance light travels in one year (9.46 trillion km), not a measure of time.


Thus, the correct answer is (C) Cosmic year.