A gas undergoes three processes: (1) Adiabatic expansion, (2) Isothermal compression, (3) Isobaric compression, returning to initial state. Which statement about the net work done by the gas is true?
Correct: B
In the adiabatic expansion (1), the gas does positive work. During isothermal compression (2), work on the gas is greater in magnitude than expansion, making net work negative. Isobaric compression (3) adds to negative work. Hence, the net work done by the gas is always negative (B).