Thermodynamics Question 247
Question: When a system is taken a from state i to state f along the path iaf, it is found that $ Q=50 $ cal and $ W=20cal. $ , Along the path ibf $ Q=36 $ cal. W along the path ibf is
Options:
A) 14 cal
B) 6 cal
C) 16 cal
D) 66 cal
Show Answer
Answer:
Correct Answer: B
Solution:
[b] For path iaf, $ Q=50cal~~W=20cal $
By first law of thermodynamics, $ \Delta U=Q-W=50-20=30cal. $ For path ibf $ Q’=36cal $
$ W=? $ or, $ W=Q’-\Delta U’ $
Since, the change in internal energy does not depend on the path,
therefore $ \Delta U’=30cal $
$ \therefore W=Q’-\Delta U’=36-30=6cal. $
