An ideal gas undergoes four different processes from the same initial state (Fig.). Four processes are adiabatic, isothermal, isobaric and isochoric. Out of 1, 2, 3 and 4 which one is adiabatic.
As we know,
When a thermodynamic system undergoes a change in such a way that no exchange of heat takes place between it and the surroundings, the process is known as adiabatic process.
As per the given (P−V) curve, the curve 4 pressure is constant, so this is an isobaric process.
For the curve 1, volume is constant, so it is isochoric process.
Between curves 3 and 2, curve 2 is steeper (more slope), so it is adiabatic and the remaining curve 3 is isothermal.
Final Answer: (c).