Question

All of the following is a unit of time except
A. Seconds
B. Months
C. Years
D. Light years

Answer 1

HintLight years is a unit of distance. It is actually the distance that light can travel in one year. It is used to express astronomical distances and is equal to about 9.5 trillion kilometers or 5.9 trillion miles.
There are 12 months in a year.

 Complete step-by-step solution:
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. This is also known as the midst unit.
The SI unit of time is Second.
Month and Year are also a unit of time.
One year consists of 12 Months.
But a light-year is a unit of distance. It is actually the distance that light can travel in one year. It is used to express astronomical distances and are equal to about 9.5 trillion kilometers or 5.9 trillion miles.

So, Light years are not a unit of time. Hence, the correct answer is D.

Note:- Fundamental Units are the units of those physical quantities which are independent to each other. There are seven fundamental quantities and units.
There is a unique system of measurement with an official status in nearly every country in the world which is known as International System of Unit, consisting seven base or fundamental units that are second (time, s), metre (length, m), kilogram (mass, kg), ampere (electric current, A), kelvin (temperature, K), mole (amount of substance, mol) and candela (luminous intensity, cd).
There is another system of units, which were used earlier, called CGS (Gram Centimetre Second) units.