A total of of heat is transferred from a hot reservoir at to a cold reservoir at in…

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

Problem

A total of

500\,\text{J}

of heat is transferred from a hot reservoir at

450\,\text{K}

to a cold reservoir at

300\,\text{K}

in two different ways: (i) directly in one step, (ii) in two equal steps via an intermediate reservoir at

375\,\text{K}

(so that

250\,\text{J}

flows in each step). Assuming the reservoir temperatures remain constant, which option gives the magnitude of the total entropy produced (

\Delta S_{\text{univ}}

) in the two cases? (a) Case (i):

0.278\,\text{J K}^{-1}

, Case (ii):

0.556\,\text{J K}^{-1}

(b) Both cases:

0.556\,\text{J K}^{-1}

0.556\,\text{J K}^{-1}

, Case (ii):

0.278\,\text{J K}^{-1}

(d) Case (i):

0.556\,\text{J K}^{-1}

, Case (ii):

0.139\,\text{J K}^{-1}