On a Pv diagram what does the area under die process curve r
     On a P-v diagram, what does the area under die process curve represent?  Is it possible to compress an ideal gas isothermally in an adiabatic piston-cylinder device? Explain. 
  
  Solution
2)Area under the process curve represents the net work done during the process.
3)Q=U+W
With adiabatic Q=0
If some work is done then U will be non zero.And since U is internal energy change it should result in temperature change.
With isothermal process we r also saying U=0 but that would imply that W=0.However we did work since compression requires work to be done.So it is not possible.

