Question

The adabiatic index, gamma, is sometimes called the ratio of specific heats. It’s the ratio of the amount of heat needed to change an object’s temperature at constant pressure to the amount of heat needed to change the same object’s temperature at constant volume. Explain why there is a difference

Answer 1

During Constant Pressure: When heat is added to the system to rise its temperature by 1^o C, the system absorbs some heat in expansion also, utilizing some of the heat in work done to expand, therefore, heat required will be more to compensate for the utilized heat for expansion . The required heat is called specific heat at constant pressure (C_P )

During constant volume : Since volume is kept constant, the system cann't expand, and therefore entire heat is utilized in rising the temperature by 1^o C, and hence heat required is comparatively less. The required heat is called specific heat at constant volume (Cv)

Conclusion: C_P > C_v