Relation Between Specific Heats

The following relations between the two specific heats (i.e. Cp and Cv) are important.

1. The difference of two specific heats is equal to gas constant (R), i.e.

Cp - Cv = R

2. The ratio of two specific heats (i.e. Cp / Cv) is known as adiabatic index and it is represented by a Greek letter gamma (Ɣ).

We Know That Cp - Cv = R

or Cp/Cv = 1 + R/Cv

Ɣ = 1 + R/Cv

Since Cp is always greater than Cv therefore the value of Ɣ is always greater than unity.

Note: The value of Ɣ for air is 1.4.