Given below are two statements:
Statement I: If heat is added to a system, its temperature must increase.
Statement II: If positive work is done by a system in a thermodynamic process, its volume must increase.
In the light of the above statements, choose the correct answer from the options given below

Question

Given below are two statements:

Statement I: If heat is added to a system, its temperature must increase.

Statement II: If positive work is done by a system in a thermodynamic process, its volume must increase.

In the light of the above statements, choose the correct answer from the options given below

G1 Physics · Accepted Answer

Statement I is false. Heat can be added without increasing temperature, for example during an isothermal expansion or during a phase change. Statement II is true for the usual mechanical work of a gas: W = ∫P dV If the gas does positive work, then dV is positive overall, so the gas expands. Therefore Statement I is false and Statement II is true. Hence option D follows.