Light year is the unit of which of the following 1) Distance 2) Time 3) Speed 4) Intensity of Light

Light year is the unit of the 

A. Distance 

B. Time 

C. Speed 

D. Intensity of Light

Answer: 

Light year is used to express astronomical distances and is a large unit of length. It is equivalent to 9.46 trillion kilometres (9.46 x 1012 km) or 5.88 trillion miles (5.88 x 10¹² mi). According to the definition given by the International Astronomical Union (IAU), a light year is stated as the distance that light travels in a vacuum in one Julian year that is about 365.25 days. The term light year is sometimes misunderstood as a unit of time.

It sometimes expresses the distances to stars and other distances on a galactic scale. The most commonly used unit in professional astronomy is the parsec which has been derived from astrometry. 

The correct option is (1) Distance

The light year is the unit of distance. It is expressed as the distance a light photon travels in the vacuum in 365 days. It is denoted by ‘ly’. The value of one- light year is always constant. 

The value of a one-light year can be mathematically represented in kilometres.

That is,

One light year

ly= 9.4607 × 10¹² km

Similarly,

• 1 light-year = 5.88 × 10¹² miles (in miles)
• 1 light-year = 63241 au (in astronomical units).