Question 104: Units , Dimensions and Error Analysis

Question

Given below are two statements :
Statements I : Astronomical unit (Au), Parsec (Pc) and Light year (ly) are units for measuring astronomical distances.
Statements II : $$\mathrm{Au} < \mathrm{Parsec} (\mathrm{Pc}) < \mathrm{ly}$$
In the light of the above statements, choose the most appropriate answer from the options given below:

Accepted Answer

Statement I is correct. Astronomical unit (AU), parsec (pc), and light year (ly) are indeed units for measuring astronomical distances.
However, Statement II is incorrect. The correct order of these units is:
$$\mathrm{AU} < \mathrm{ly} < \mathrm{Parsec} (\mathrm{Pc})$$
1 AU is the average distance from the Earth to the Sun, which is about 93 million miles or 150 million kilometers.
1 light year is the distance that light travels in one year in a vacuum, which is approximately 9.461 trillion kilometers (5.878 trillion miles).
1 parsec is equal to about 3.26 light years, or approximately 30.9 trillion kilometers (19.2 trillion miles). Parsec (parallax of one arcsecond) is the distance at which an arc of length $1 \mathrm{Au}$ subtends an angle of one arcsecond $(1 \mathrm{Pc}=3.26 \mathrm{ly})$.
So, the correct answer is Statement I is correct but Statement II is incorrect.

Answer

Both Statements I and Statements II are incorrect.

Answer

Both Statements I and Statements II are correct,

Answer

Statements I is incorrect but Statements II is correct.

Answer

Statements I is correct but Statements II is incorrect.

Units , Dimensions and Error Analysis

Choose the correct answer: