JEE Main2013PhysicsKinetic Theory of GasesActual
This question has Statement-1 and Statement-2. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement 1: The internal energy of a perfect gas is entirely kinetic and depends only on absolute temperature of the gas and not on its pressure or volume. Statement 2: A perfect gas is heated keeping pressure constant and later at constant volume. For the same amount
Options
- AStatement-1 is true, Statement- 2 is true and Statement -2 is the correct explanation of Statement-1.
- BStatement-1 is true, Statement-2 is false.
- CStatement-1 is true, Statement-2 is true but Statement-2 is not the correct explanation of Statement-1.
- DStatement-1 is false, Statement-2 is true.
Correct answer
C. Statement-1 is true, Statement-2 is true but Statement-2 is not the correct explanation of Statement-1.
Step-by-step solution
Internal energy of a system is the energy possessed by the system due to molecular motion and molecular configuration. Internal energy u=u_k+u_p For an ideal gas there is no molecular attraction u _ p =0 Internal energy u = u _ k (i.e., internal kinetic energy) and u = u _ k = 3 2 RT At constant pressure ( Q )_ P = C _ p T At constant volume ( Q )_ v = C _ v T As C _ P > C _ V ( T )_ P < ( T )_ V