The document discusses systems of units used to measure physical dimensions. It explains that dimensions include properties like length, mass, and volume. Standard units of measurement are assigned to dimensions, such as meters for length. The main system discussed is the SI system, which has six primary units that can be used to describe all other derived units commonly used in practice.

1. SYSTEM OF UNITS1

2. DIMENSIONThe measurable properties used to describe the physical state of the body or system are known as its dimensionsFor example length, mass, volume etc2

3. UNITSFor determining the magnitude of any dimension we use agreed units of measurements such asFor length we use meter, ft etc3

4. The SI System of unitsThe SI system consists of six primary units, from which all quantities may be described

5. Secondary units are used in general practice which are made from combinations of these primary units4

6. Primary Units5

7. Derived Units6