Q 11-11-151JEE MainJEE Main 2019 (9 Jan, Shift 1)Easy
A gas can be taken from A to B via two different processes ACB and ADB shown in the figure. When path ACB is used 60 J of heat flows into the system and 30 J of work is done by the system. If the path ADB is used then work done by the system is 10 J, the heat flows into the system in the path ADB is
Answer: (C) $40\ \text{J}$
Internal energy is a state function, so $\Delta U_{A\to B}$ is the same on both paths. From path ACB:
$$\Delta U = Q - W = 60 - 30 = 30\ \text{J}$$
For path ADB:
$$Q = \Delta U + W = 30 + 10 = 40\ \text{J}$$
Solution by Sreeraj P, M.Sc Physics