Question

What are SI units? How many SI units are defined for fundamental quantities?

Answer 1

1. In earlier times, physical quantities measured in different units have different magnitudes.
2. thus, it became inconvenient and difficult to compare the results.
3. So, there was a need for having a universal system of units.
4. This system is called SI (Système International d'Unités) unit system.
5. In English it is called the International System of Units.
6. It is the most widely used system of measurement around the world.
7. It is made up of seven fundamental units of measurement i.e. mass, length, time, current, temperature, quantity of substance and luminous intensity.
8. For every fundamental quantity only one unique SI unit is defined.