A system can be taken (p1 , V1 ) to (p2 ,V2 ) , by two different methods. Let ∆Q and ∆W represent the heat given to the system and the work done by the system. Which of the following must be the same in both the methods ?

Q: A system can be taken (p₁ , V₁ ) to (p₂ , V₂ ) , by two different methods. Let ∆Q and ∆W represent the heat given to the system and the work done by the system. Which of the following must be the same in both the methods ?

(a) ∆Q

(b) ∆W

(c) ∆Q + ∆W

(d) ∆Q – ∆W

Ans:(d)

Sol: A system can be taken (p₁ , V₁ ) to (p₂ , V₂ )  by two different methods . Since initial and final states are same for two processes .

∆U₁ = ∆U₂

∆U₁ = ∆U₂ = ∆Q – ∆W