JEE PYQ: Thermodynamics Question 37
Question 37 - 2019 (09 Jan Shift 1)
A gas can be taken from A to B via two different processes ACB and ADB.
[P-V diagram showing rectangular path: C at top-left, B at top-right, A at bottom-left, D at bottom-right]
When path ACB is used 60 J of heat flows into the system and 30J of work is done by the system. If path ADB is used work done by the system is 10 J. The heat flow into the system in path ADB is :
(1) 40 J
(2) 80 J
(3) 100 J
(4) 20 J
Show Answer
Answer: (1)
Solution
$\Delta U$ remains same for both paths ACB and ADB.
$\Delta Q_{ACB} = \Delta W_{ACB} + \Delta U_{ACB}$
$60$ J $= 30$ J $+ \Delta U_{ACB}$
$\Rightarrow U_{ACB} = 30$ J
$\therefore \Delta U_{ADB} = \Delta U_{ACB} = 30$ J
$\Delta Q_{ADB} = \Delta U_{ADB} + \Delta W_{ADB}$
$= 10$ J $+ 30$ J $= 40$ J
BETA
