Question

Which of the following is not a unit of time?

• A. second
• B. parsec
• C. year
• D. light year

Answer 1

Answer: (B), (D)

light year

Reason for correct option-

1. Parsec- it is a unit to express the distance of galaxies and stars hence it is not a unit of time
2. light year - light-year is the distance traveled by light in 1 year. hence it measures distance not time

Reason for incorrect option-

1. Second - It is the SI unit of time
2. Year - time is taken by earth for one full revolution around the sun.