Heat And Thermodynamics Flashcards
Why does the pressure of a gas in a car tyre increase when it is driven through some distance?
This is due to the work done against friction between road and tyre. This work done appears as heat. This heat is absorbed by the gas molecule. It increases the average kinetic energy of molecules. As pressure is directly proportional to K.E., so pressure of gas is increased.
Specific heat of a gas at constant pressure is greater than specific heat at constant volume. why?
When a gas is heated at constant pressure then,
1. A part of heat is used to do work on piston.
2. Rest of heat is used to increase temperature through 1K.
When gas is heated at constant volume then all the heat absorbed is used to increase temperature through 1K.
Give an example of a process in which no heat is transferred to or from the system but the temperature of the system changes.
In adiabatic process no heat enters or leaves the system take place but temperature of the system changes.
