Question

Adiabatic expansions of an ideal gas is accompanied by
A decrease in $\Delta E$
B increase in temperature
C decrease in $\Delta S$
D no change in any one of the above properties

Answer 1

An ideal gas is a theoretical gas made up of a large number of randomly moving point particles with no interparticle interactions. Because it obeys the ideal gas law, a simplified equation of state, and is susceptible to statistical mechanics analysis, the ideal gas notion is helpful. If the interaction is fully elastic or viewed as point-like collisions, the criterion of zero interaction can frequently be waived.

Complete answer:
An adiabatic process is a sort of thermodynamic process that happens without the transmission of heat or mass between the thermodynamic system and its environment in thermodynamics. An adiabatic process, unlike an isothermal process, only transmits energy to the environment as work. The adiabatic process is a crucial notion in thermodynamics that supports the hypothesis that explains the first rule of thermodynamics.
Adiabatic expansion occurs when an external force works on a system rather than using the gas's own energy, resulting in a decrease in the temperature of the gas molecules. It has to do with thermodynamic concepts. The term adiabatic refers to a process in which a system does neither absorb or lose heat energy.
When a gas is compressed, its temperature rises; however, when the temperature of the same gas falls while the pressure remains constant, it is considered to be in the adiabatic expansion phase. When a gas is in the isothermal process phase, it expands freely. There is no gain or loss of heat in an adiabatic expansion phase, thus “Q” remains zero. Also, because the adiabatic process occurs fast, there is no time for heat to be exchanged, indicating that the system is adequately insulated. In an adiabatic operation, the ideal gas equation from the first law of thermodynamics may be expressed as:
$W=-\text{ }\\!\\!\Delta\\!\\!\text{ }E$
$\mathbf{n}.\mathbf{Cv}.\mathbf{dT}\text{ }=\text{ }-\text{ }\mathbf{P}.\mathbf{dV}$

Hence option a is correct.

Note:
Adiabatic cooling happens when the pressure on an adiabatically separated system is reduced, enabling the system to expand and perform work on its surroundings. When the pressure on a parcel of gas is dropped, the gas inside the parcel is allowed to expand; as the volume grows, the temperature lowers as the internal energy of the parcel decreases. With orographic lifting and lee waves, adiabatic cooling occurs in the Earth's atmosphere, resulting in pileus or lenticular clouds.