1. Tardigrade
  2. Question
  3. Physics
  4. The p-V diagram of a system undergoing thermodynamic transformation is shown is figure. The work done by the system in going from A → B → C is 50 J and 20 cal heat is given to the system. The change in internal a energy between A and C is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The p-V diagram of a system undergoing thermodynamic transformation is shown is figure. The work done by the system in going from A $ \to $ B $ \to $ C is 50 J and 20 cal heat is given to the system. The change in internal a energy between A and C isPhysics Question Image

CMC MedicalCMC Medical 2010

Solution:

From the first law of thermodynamics, if an amount of heat Q is given to a system, a part of it will be used in increasing the internal energy $ (\Delta U) $ of the system and rest in doing work (W) by the system. Therefore, $ Q=\Delta U+W $ $ \Rightarrow $ $ \Delta U=Q-W $ Given, $ Q=20\,cal=20\times 4.2J=84\,J $ $ W=50\,J $ $ \therefore $ $ \Delta U=(84-50)J=34\,J $