Unit of Measurement

Description:

To measure a physical quantity, we need some standard measurements of that quantity and this standard measurement is known as unit. All measurements of this quantity are multiples of unit. Measurement is simply a comparison of physical quantity with unit.

The measurement of a physical quantity is mentioned in two parts, the first part gives how many times of the standard unit and the second part gives the name of the unit. For example, we have to study for 2 hours. The numeric part 2 says that it is 2 times of the unit of time and the second part hour says that the unit chosen here is an hour.

Thus,

Measurement = numerical value × unit

System of units

Commonly used systems of units are −

• The FPS system (Foot, Pound and Seconds system) developed by British.

• The CGS system (Centimetre, Gram and Seconds system) developed by French.

• The SI system (System International). The SI system uses the MKS system (Metre, Kilogram and Second system).