Thermodynamics Ques 8
8. Figure below shows two paths that may be taken by a gas to go from a state $A$ to a state $C$.
In process $A B,$ $ 400$ $ J$ of heat is added to the system and in process $BC, $ $100 $ $J$ of heat is added to the system. The heat absorbed by the system in the process $AC$ is $500$ $J$
[2015]
(a) $500$ $ J$
(b) $460$ $ J$
(c) $300$ $ J$
(d) $380$ $ J$
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Answer:
Correct Answer: 8.(b)
Solution:
- (b) In cyclic process $ABCD$
$ Q _{\text{cycle }}=W _{\text{cycle }} + \Delta U $
$Q _{AB}+Q _{BC}+Q _{CA}=$ area of $\triangle ABC$ $+400+100+Q _{C \to A}=\frac{1}{2}(2 \times 10^{-3})(4 \times 10^{4})$
$\Rightarrow Q _{C \to A} = - 460$ $ J$
$\Rightarrow Q _{C \to A} = + 460$ $J$
BETA
