Class 11 Physics Ch 11 Notes

• Important class 11 physics ch 11 exercise solutions from Punjab Textbook.
• What are the main postulates of kinetic theory of gases?
• What are the main postulates of kinetic theory of gases? Ans: Main Postulates: (i) A finite volume of gas consists of very large number of molecules. (ii) The size of molecules is much smaller than the separation between molecules. (iii) The gas molecules are in random motion and may change their direction of motion after every collision. (iv) Collision between gas molecules themselves and with the wall of container are assumed to be perfectly elastic. (v) Molecules exert no force on each other except during a collision.
• Define Boyle’s law. How it can be derived the expression of gas.
• Define Charles’s law. How it can be derived the expression of gas.
• Define internal energy. How can we increase internal energy?
• Important class 11 physics ch 11 question answer from Punjab Textbook.
• State first law of thermodynamics and give its mathematical form: Ans: Statement: When the heat Q is added to a system, this energy appears as an increase in the internal ΔU stored in the system plus the work done W by the system on its surroundings. Q = ΔU + W.
• What is isothermal process? 
• What is adiabatic process?
• Define molar specific heat. Also discuss its types.
• Differentiate between reversible and irreversible process.
• Important class 11 physics ch 11 numerical from Punjab Textbook.
• State second law of thermodynamics.
• Write down two statements of Carnot’s Engine. Also write down its four steps.
• What is triple point of water?
• Name the four strokes of petrol engine. 
• Why spark plug is not needed in a diesel engine?
• What is entropy? Give its mathematical form. Also write its unit.
• Why the average velocity of the molecules in a gas container is zero but the average of the squares of velocities is not zero?
• Why does the pressure of gas in a car tyre increases when it is driven through some distance?
•  A system undergoes from state P1V1 to P2V2 as shown in fig. What will be the change in internal energy?
•  A variation of volume by pressure is given in fig. 11.13. a gas is taken along the paths ABCDA, ABCA and A to A. What will be the change in internal energy?
• Specific heat of a gas at constant pressure is greater than specific heat at constant volume. Why?
• Give an example of a process in which no heat is transferred to or from the system but the temperature of the system changes. 
• Is it possible to convert internal energy into mechanical energy? Explain with an example.
• Is it possible to construct a heat engine that will not expel heat into the atmosphere?
• A thermos flask containing milk, as a system is shaken rapidly. Does the temperature of milk rise?
• What happens to the temperature of the room? When an air conditioner is left running on a table in the middle of the room?
• Can the mechanical energy be converted completely into heat energy? If so give an example.
• Does entropy of a system increases or decreases due to friction?
• Give an example of a natural process that involves an increase in entropy?