explain why cp is always greater than cv
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✔️✔️using the First law of thermodynamics:-
✔️✔️At constant Pressure
dQ=dU+P.dV-------------------(1)
✔️✔️At Constant Volume,
dQ=dU+P.dV
Since dV=0
Therefore dQ=dU------------------(2)
✔️✔️Therefore Cp=dU+P.dV
Cv=dU
✔️✔️Therefore using the above relation Cp is greater than Cv.
--------------------- or ---------------------
⭕️At constant volume, heat is required only to increase the internal energy of system while At constant Pressure heat is needed for increasing Internal energy as well as for doing the work to displace the piston of system through a distance.
⭕️Therefore Cp has a greater value than Cv.
===== Answer ======
Why cp is always greater than cv ??
Ans ----- At a constant volume heat is required only to increase the internal energy system while at constant pressure it is needed to both increase the internal heat as well as to displace the piston of system , so CP is greater.........
And.... we can also explain this by the first law of thermodynamics :-
At constant pressure ---
dQ = dV + P.dV ....... (1)
At constant volume ------
cp = dU + P.dV ........ (2)
Cv = dU ....
So.. CP is greater than CV..
Thank you