Question

A system is allowed to move from state A to B following path ACB by absorbing 80 J of heat energy. The work done by the system is 30 J. The work done by the system in reaching state B from A is 10 J through path ADB. Which statements are correct? (i) Increase in internal energy from state A tc state B is 50 J. (ii) If path ADB is followed to reach state B, $ \Delta E=50J $ . (iii) If work done by the system in path AB is 20J,the heat absorbed during path AB = 70 J. (iv) The value $ {{E}_{C}}-{{E}_{A}} $ is equal to $ {{E}_{D}}-{{E}_{B}} $ . (v) Heat absorbed by the system to reach B from A through path ADD is 60 J.

• A. $ \text{I,V} $
• B. $ \text{I,III,V} $
• C. $ \text{I, II, III, V} $
• D. $ \text{I,IV,V} $

Answer 1

Answer: (C)

$ ACB=AC+BC $ $ ADB=AD+BD $ Heat absorbed $ 80J $ Work done by the system $ =10J $ $ \therefore $ $ W=-10J $ $ \therefore $ $ W=-30 $ Also $ W=-10J $ $ \therefore $ $ {{E}_{B}}-{{E}_{A}}=50J $ $ \therefore $ $ Q=50+10=60J $