Since the gas kept in the container is suddenly compressed, there is very little time for any heat to allow to enter or leave the container. Hence, it must be very nearly an adiabatic process. If the temperature remains constant during this process, then the process may also be isothermal. Option (a) is incorrect because it must be very nearly adiabatic but might not be completely depending on how

sudden the process is.

Option (b) is incorrect because if the compression is indeed done suddenly, then the temperature of the gas does not remain constant, and it may not be isothermal. It changes with the pressure and the volume of the gas according to the formulae:

i.

ii. PVᵞ = constant

Where,

P1, V1, T1: initial values of pressure, volume and temperature

P2, V2, T2: final values of pressure, volume and temperature