Question

The temperature of the system decreases in the process of:

• A. free- expansion
• B. adiabatic expansion
• C. isothermal expansion
• D. isothermal compression

Answer 1

The correct option is B

adiabatic expansion

The explanation for the correct option

Option B adiabatic expansion

• Adiabatic expansion is described as an expansion for which there is no heat transfer between the system and its environment.
• The system uses its internal energy to perform work.
• A system performs work during adiabatic expansion, which causes it to lose heat to the environment.
• As a result, the system's temperature drops.

The explanation for incorrect options:

Option A Free expansion:

• The temperature does not change since the internal energy remains unchanged.
• A gas expands into an insulated, evacuated chamber by an irreversible process known as free expansion.
• Since the temperature doesn't change throughout the free expansion, the pressure must also decrease.

Option C isothermal expansion

• A thermodynamic process known as an isothermal process keeps the system's temperature constant.
• Because heat is transferred into or out of the system so slowly, thermal equilibrium is retained.
• Thus the temperature stays constant during the isothermal expansion process.

Option D isothermal compression

• Isothermal compression is the process of decreasing the volume of a specific mass of fluid (system) while maintaining that fluid's constant temperature.
• As a result, the fluid's internal energy(system) also doesn't change.

Thus Option B adiabatic expansion is the correct option.