Which one of the following is a reason why astronomical distances are measured in light-years?

[UPSC Civil Services Exam – 2021 Prelims]

(a) Distances among stellar bodies do not change.

(b) Gravity of stellar bodies does not change.

(c) Light always travels in straight line.

(d) Speed of light is always same.


Answer: (d)        

Explanation:

  • A light-year is a measurement of distance in space.
  • The astronomical distances are measured in light-years because, the speed of light is constant throughout the universe and is known to high precision. In a vacuum, light travels at 670,616,629 mph (1,079,252,849 km/h).
  • To find the distance of a light-year, you multiply this speed by the number of hours in a year (8,766). The result: One light-year equals 5,878,625,370,000 miles (9.5 trillion km).

Consider the following statements:                                                                   The Parliament of India can place a particular law in the Ninth Schedule of the Constitution of India. The validity of a law placed in the Ninth Schedule cannot be examined by any court and no judgement can be made on it. Which of the statements given above is/are correct?

Consider the following statements:                                               

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Consider the following statements:                                                         The Parliament of India can place a particular law in the Ninth Schedule of the Constitution of India. The validity of a law placed in the Ninth Schedule cannot be examined by any court and no judgement can be made on it. Which of the statements given above is/are correct?

Consider the following statements:                                               

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