NextMockપરીક્ષાઓ શોધો, દા.ત. SSC CGL, UPPSC, Lekhpal
UPSC PYQPrelims 2021

Civil Services Examination · પ્રશ્ન 76

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

  1. Distances among stellar bodies do not change.
  2. Gravity of stellar bodies does not change.
  3. Light always travels in straight line.
  4. Speed of light is always same.
જવાબ બતાવો અને સમજૂતી

જવાબ: (D) Speed of light is always same.

સમજૂતી

The speed of light in vacuum is constant, so the distance light travels in a year is a fixed, convenient unit.