Fundamental and derived quantities:
Generally, physical quantities are classified into two types, namely, (i) Fundamental quantities and (ii) Derived quantities.
A set of physical quantities which cannot be expressed in terms of any other quantities are known as “Fundamental quantities”. Their corresponding units are called “Fundamental units”.
There are seven fundamental physical quantities in SI Units (System of International Units).
All other physical quantities which can be obtained by multiplying, dividing or by mathematically combining the fundamental quantities are known as “derived quantities”.
Their corresponding units are called “Derived units”. Some of the derived quantities and their units are given in table 1.1.
Table 1.1 Some of the derived quantities and their units in SI System of units