Question

What happens to the temperature of a gas in adiabatic expansion?

• A. Reduces
• B. Increases
• C. Remains constant
• D. Need additional information

Answer 1

The correct option is A

Reduces

In an adiabatic expansion process the change in the state of the gas happens so quickly that there is no time for any heat transfer to take between the system and the environment.
$\Rightarrow Q=0$.
Therefore from first law of thermodynamics it follows that,
$\Delta E_{int}=-W$.
Whenever the gas expands in a system the work done by the gas is positive.
So the change in $E_{int}$ is negative implying that there is a drop in temperature.