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

JEE MAIN 2023, Medium
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Statement $I:$ $\Delta Q > 0$

According to $1^{\text {st }}$ law of thermodynamics

$\Delta Q =\Delta U + W$

If $\Delta Q > 0, \Delta U < 0$ and $W > 0$ is also possible.

Hence $\Delta T < 0$, so $T$ decreases.

Statement $I$ is false

Statement $II:$ W $ > 0$

$\therefore \int Pdv > 0$

Therefore volume of system must increase during positive work done by the system.

Statement $II$ is true

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