Question

If the heat of $110\, J$ is added to a gaseous system, whose internal energy is $40\, J$, then the amount of external work done is

• A. 180 J
• B. 70 J
• C. 110 J
• D. 30 J

Answer 1

Answer: (B)

70 J

Answer 2

Heat added to the system $\Delta Q=110\, J$
Internal energy $\Delta u=40\, J$
External work done is given by
$\Delta W=\Delta Q-\Delta u=110-40=70\, J$