Question

A quantity of air $(\gamma =1.4)$ at $27^{\circ }C$ is compressed suddenly, the temperature of the air system will

• A. fall
• B. rise
• C. remain unchanged
• D. first rise and then fall

Answer 1

Answer: (B)

From first law of thermodynamics
$\Delta U=Q-W$
where $\Delta U$ is change in internal energy, $W$ the work and $Q$ the energy.
When air is compressed, it means work is done on the system, so internal energy increases, it means temperature increases.