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
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
| List $I$ | List $II$ |
| $A$ Isothermal Process | $I$ Work done by the gas decreases internal energy |
| $B$ Adiabatic Process | $II$ No change in internal energy |
| $C$ Isochoric Process | $III$ The heat absorbed goes partly to increase internal energy and partly to do work |
| $D$ Isobaric Process | $IV$ No work is done on or by the gas |
Choose the correct answer from the options given below :

