Question

No heat is lost or gained by the system to or from the surroundings but, work $W$ is done on the system. Which of the following statements is correct?

• A. $△U=W,$ wall is insulated
• B. $△U=Q,$ diathermic walls
• C. $△U=Q-W,$ closed system.
• D. $△U=Q+W,$ open system

Answer 1

The correct option is A $△U=W,$ wall is insulated

This is possible for an adiabatic wall or an insulated wall in which, no heat exchange happens. And thus, $q=0$. Therefore, $△U=W_{adibatic}$.