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.

When the system is returned from state `B` to `A` along the curve path, the work done on the system is `20 J`.
Does the system absorb or literate heat and by how much ?
A. `- 70 J`, heat is liberated.
B. `-60 J`, heat is liberated
C. `+70 J`, heat is absorbed
D. `+60 J`, heat is absorbed.

Answer 1

Correct Answer - A
For `B` to `A`,
`Delta E= -50 J`
`w= +20 J`
`q= -50-20= -70`
heat is liberate.