Question

A sample of an ideal gas is taken through the cyclic process abca as shown in the figure. The change in the internal energy of the gas along the path ca is $-180\,J$. The gas absorbs $250\, J$ of heat along the path ab and $60\, J$ along the path $bc$. The work done by the gas along the path $abc$ is :

• A. 100 J
• B. 120 J
• C. 140 J
• D. 130 J

Answer 1

Answer: (D)

130 J

Answer 2

\begin{array}{c|c} & \Delta E & \Delta W & \Delta Q \\\ \hline ab & & &250 \\\ bc & & 0 &60 \\\ ca & -180 && \end{array}
\begin{array}{c|c} & \Delta E & \Delta W & \Delta Q \\\ \hline ab & 120 & 130 &250 \\\ bc & 60 & 0 &60 \\\ ca & -180 && \end{array}