Multiple choice physics heat engine: second law of thermodynamics second law of thermodynamics the second law of thermodynamics second law of thermodynamic Which of the following is not a path function ? $\Delta$ Q $\Delta$ Q + $\Delta$ W $\Delta$ W $\Delta$ Q - $\Delta$ W Reveal answer Fill a bubble to check yourself D Correct answer Explanation $\Delta Q=\Delta U+\Delta W\ \Delta Q-\Delta W=\Delta U$$\Delta U$ is internal energy which is independent of path.