Unit Systems

Unit Systems

We need three things for a perfect measurement. They are: an instrument, a standard quantity and an acceptable unit.

Let us say that the length of the book be 30 cm. Here, the length is the physical quantity, ruler is the instrument, 30 is the magnitude and ‘cm’ is the unit. This process is called measurement.

In the above activity the values of all the students will not be same. Similarly, people in various parts of the world are using different systems of units for measurement. Some common systems of units are as follows.

1. FPS System (Foot for length, Pound for mass and Second for time)

2. CGS System (Centimetre for length, Gram for mass and Second for time)

3. MKS System (Meter for length, Kilogram for mass and Second for time)

The ‘CGS’, ‘MKS’ and SI units are metric systems of units and ‘FPS’ is not a metric system. It isa British system of units.