In which of the following situations, the entropy change is negative?

1.	In which of the following situations, the entropy change is negative?
A.	Air expands isothermally from 6 bar to 3 bar
B.	Air is compressed to half of it volume at constant pressure
C.	Air is supplied with heat at constant volume till its pressure is doubled
D.	Air expands adiabatically from 6 bar to 3 bar
Answer» C. Air is supplied with heat at constant volume till its pressure is doubled

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In which of the following situations, the entropy change is negative?

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