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Question
Two samples A and B are initially kept in the same state. Sample A is expanded through an adiabatic process and the sample B through an isothermal process. The final volumes of the samples are the same. The final pressures in A and B are pA and pBrespectively.
Options
pA > pB
pA = pB
pA < pB
The relation between pA and pB cannot be deduced.
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Solution
pA < pB
Let the initial states of samples A and B be i and the final states of samples B and A be fand f', respectively. Let the final volumes of both be Vo. As sample A is expanded through an adiabatic process, its curve in the p-V diagram is steeper than that of sampleB, which is expanded through an isothermal process. Therefore, from the p-V diagram, pA < pB.
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