Thermodynamics Question 28
Question: Helium at $ 27^{o}C $ has a volume of 8 litres. It is suddenly compressed to a volume of 1 litre. The temperature of the gas will be $ [\gamma =5/3] $ [CBSE PMT 1993; MP PMT 1999; Pb. PMT 2002]
Options:
A) $ \frac{R}{\gamma -1}(T _{2}-T _{1}) $
B) $ \frac{R}{\gamma -1}(T _{1}-T _{2}) $
C) $ R(T _{1}-T _{2}) $
D) Zero
Show Answer
Answer:
Correct Answer: A
Solution:
$ \Delta U=-\Delta W=-\frac{R(T _{1}-T _{2})}{(\gamma -1)} $
$ =\frac{R(T _{2}-T _{1})}{\gamma -1} $
