Question

If the first law of thermodynamics is represented by $\Delta u=q+w$. The $q$ & $w$ represent?

• A. Work done on the system & heat added to the system respectively
• B. Work done by the system & heat added to the system respectively
• C. Heat added to the system & work done on the system respectively
• D. Heat take from the system & work done on the system respectively

Answer 1

The correct option is C Heat added to the system & work done on the system respectively

Since $q$ is positive, it represents the heat added to the system.

Since $w$ is positive, it represents the work done on the system.