1100Rlog2
An engine using 1 mole of an ideal gas initially at V1 = 33.2 litre and 400 K performs a cycle ABCDA consisting of four steps: (1) an isothermal expansion at T = 400 K to twice its initial volume (AB), (2) cooling at constant volume to T = 300 K (BC), (3) an isothermal compression to its original volume (CD) and heating at constant volume to its original temperature at 400 K (DA).
question: Net work done for the cyclic process ABCDA is [where R = gas constant
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10 Answers
1edited the thing ..
1) isothermal expansion
so, WAB = + 400nRlog(v2/v1)
= + 400nRlog2
2) isochoric proc. so, work done =0
3) isothermal contraction
so, WCD = 300nRlog(v1/v2)
= - 300nRlog[1/2] = - 300nRlog2
4) zero work done.
so net work done = 100nRlog2.
1oh shit ...
i thot one is expansion ... n the other contraction dats y....
1357The final magnitude of work will itself tell, if it was expansion or compression
so don't make these mistakes