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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.                                                             [JEE ONLINE 23-04-2013]

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 1: A perfect gas is heated keeping pressure constant pressure is lower than that at constant volume.

A)  Statement-1 is true, Statement-2 is true, and Statement 2 is the count explanation of Statement 1.

B)       Statement -1 is true, Statement-2 is false.

C)  Statement 1 is true, Statement 2 is true but Statement 2 is not the correct explanation of Statement 1.

D)  Statement -1 is false, Statement -2 is true.

Correct Answer: C

Solution :

[c] Internal energy of a system is the energy possessed by the system due to molecular motion and molecular configuration.

Internal energy

For an ideal gas there is no molecular attraction

Internal energy(i.e., internal kinetic energy)  and

At constant pressure

At constant volume

As