Thermodynamics Question 132
Question: In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas molecules gives out 20 J of heat and 10 J of work is done on the gas. If the initial internal energy of the gas was 40 J, then the final internal energy will be
[DPMT 2004]
Options:
A) 30 J
B) 20 J
C) 60 J
D) 40 J
Show Answer
Answer:
Correct Answer: C
Solution:
$ \Delta Q=\Delta U+\Delta W=(U _{f}-U _{i})+\Delta W $
Therefore $ 30=(U _{f}-40)+10 $
Therefore $ U _{f}=60J $
