NextMockపరీక్షలు వెతకండి, ఉదా. SSC CGL, UPPSC, Lekhpal
UPSC PYQPrelims 2021

Civil Services Examination · ప్రశ్న 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.
సమాధానం చూపించు & వివరణ

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

వివరణ

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