Question

In the diagram shown $Q_{\text{iaf }}=80$ cal and $W_{\text{iaf }}=50$ cal. If $W=-30$ cal for the curved path $fi$, value of $Q$ for path $fi$, will be

• A. 60 cal
• B. 30 cal
• C. -30 cal
• D. -60 cal

Answer 1

Answer: (D)

From process iaf
Find $\Delta U$ first, $\Delta Q=\Delta W+\Delta U$
$80=50+\Delta U$
$30cal=\Delta U$
Use this $\Delta U$ for process if
$\Delta Q=\Delta W+\Delta U$
$\Delta Q=-30+(-30)=-60cal$