Thermodynamics Question 18
Question: One gm mol of a diatomic gas $ (\gamma =1.4) $ is compressed adiabatically so that its temperature rises from $ 27^{o}C $ to $ 127^{o}C $ . The work done will be
Options:
A) No energy is required for expansion
B) Energy is required and it comes from the wall of the container of the gas
C) Internal energy of the gas is used in doing work
D) Law of conservation of energy does not hold
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Answer:
Correct Answer: C
Solution:
$ \Delta Q=\Delta U+\Delta W=0 $
Therefore $ \Delta W=-\Delta U $ if $ \Delta W $ is positive i.e., gas does work
then $ \Delta U $ should be negative meaning internal energy is used in doing work.
