Paper: CSIR-NET June 2012 · Subject: Physical Chemistry · Chapter: Thermodynamics · Topic: Thermodynamics – General · Marks: 2 · Difficulty: Medium
An ideal gas was subjected to a reversible, adiabatic, expansion and then its initial volume was restored by a reversible, isothermal compression. If ' q ' denotes the heat added to the system and 'w' the work done by the system, then
(a)$\mathrm{w}<0, \mathrm{q}<0$
(b)w $>0$, q $<0$
(c)$\mathrm{w}<0, \mathrm{q}>0$
(d)$\mathrm{w}>0, \mathrm{q}>0$
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
The adiabatic expansion does work on the surroundings (w > 0 by the system, q = 0); the isothermal compression back to the initial volume at the lower temperature rejects heat (q < 0).