Comparison b/w work done in adiabatic & isothermal processes

AI Thread Summary
The discussion focuses on the comparison of work done in adiabatic and isothermal processes, highlighting that the isothermal graph line is higher than the adiabatic one due to greater work done in isothermal conditions. It emphasizes the need for the same initial and final pressure and volume states for an accurate comparison. The area under the graph represents the work done by the gas, confirming that isothermal processes require more work than adiabatic ones when expanding a gas. An additional isochoric process step can be introduced for clarity in comparisons. Ultimately, the conclusion is that isothermal expansion necessitates more work than adiabatic expansion.
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Homework Statement



In the graph attached, why is isothermal graph line higher than adiabatic one??

Homework Equations





The Attempt at a Solution


At first, i had thought that work done in an isothermal process is greater than in an adiabatic process...but for comparison we would need same initial and final states (P & V) , wouldn't we?
 

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The area under the graph is the work done by the gas (W=∫PdV)

You can compare those areas and see that in an isothermal process the work done is indeed higher than in an adiabatic process.

For a proper comparison you would need indeed the same final P&V.
So introduce an extra isochoric (constant volume) process step (a vertical line in your diagram) and presto!
 
i know that.... my doubt was that P & V which are describing the state should be same(initial and final), then we can compare the work done through 2 ways: adiabatic & isothermal
but i have got it..the graph simply indicates that if we expand a gas and do it isothermally it would require more work to be done
thanks :)
 
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