Question

Which of the following statements is/are wrong?

(1) Light year is a unit of time.

(2) Astronomical unit unit (AU) is a unit of distance.

(3) Parsec is a unit of mass.

1. (2) and (3)
2. (1) and (3)
3. (3) only
4. (1) only

Answer 1

Correct Answer - Option 4 : (1) only

The correct answer is (1) only.

• A light-year is a unit of distance. Hence statement 1 is incorrect.
  • It is the distance that light can travel in one year.
  • Light moves at a velocity of about 300,000 kilometres (km) each second.
  • So in one year, it can travel about 10 trillion km.
• An astronomical unit (AU) is a unit of distance.
• Parsec is a unit of mass.

 

SI base units

Base quantity	Name	Symbol
length	meter	m
mass	kilogram	kg
time	second	sec
electric current	ampere	A
thermodynamic temperature	kelvin	K
amount of substance	mole	mol
luminous intensity	candela	cd