A heat engine operates in a single cycle by absorbing of energy as heat from a hot…

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics

Problem

A heat engine operates in a single cycle by absorbing

600\,\text{J}

of energy as heat from a hot reservoir at

500\,\text{K}

and ejecting

400\,\text{J}

of energy as heat to a cold reservoir at

300\,\text{K}

. Which statement about the change in entropy of the universe

\Delta S_{\text{univ}}

during this cycle is most accurate? (a)

\Delta S_{\text{univ}}<0

, so the cycle violates the second law. (b)

\Delta S_{\text{univ}}>0

, so the cycle is irreversible but permissible. (c)

\Delta S_{\text{univ}}=0

, so the cycle is reversible. (d)

\Delta S_{\text{univ}}>0

, so the cycle is impossible.