General Physics I:

The state of a thermodynamic system can be specified in terms of macroscopic state variables such as volume, V, temperature, T, and pressure, p. Out of these three, two are independent variables while the third may be considered as their function. In general, two of these parameters are needed to completely specify a thermodynamical system. These two types of variables are also known as extensive and intensive variables. Variables that depend on the size of a system such as volume, V, amount of substance (moles, n ), entropy, S, etc. are called extensive variables. Variables that do not depend on the size of a system such as temperature, T, pressure, p , density, \(\rho\text{,}\) etc. are called intensive variables.