Question

When a system is taken from state `A` to state `B` along path `ACB` as shown in figure below, `80 J` of heat flows into the system and the system does `30 J` of work.

If `E_(D)-E_(A)= -40 J`, the heat absorbed in the processes `AD` and `DB` are respectively
A. `q_(AD)=30J` and `q_(DB)= - 90 J`
B. `q_(AD)=-60J` and `q_(DB)= 30 J`
C. `q_(AD)=30J` and `q_(DB)= 90 J`
D. `q_(AD)=-30J` and `q_(DB)= 90 J`

Answer 1

Correct Answer - D
In `ADB` process, `DB` process is isochoric so `w_(DB)=0`
So, `Delta E_(AD)=q_(AD)+w_(AD)`
`-40=q_(AD)+(-10), q_(AD)= -30 J`
Now, `q_(AB)=q_(AD)+q_(DB), 60 =-30+ q_(DB)`
`q_(DB)=90 J`