Mechanical Engineering - Thermodynamics - Discussion
Discussion Forum : Thermodynamics - Section 1 (Q.No. 20)
20.
The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is
Discussion:
26 comments Page 1 of 3.
Ashish said:
1 decade ago
Cp/Cv = Gamma, which is the indices of the process and depends on the process. For isotropic process its 1.4, for polytropic process its n, for constant pressure process its zero, for constant volume process its infinite, for constant temperature process its equal to 1.
ABHIJEET YADAV said:
9 years ago
Cp will be greater than cv because at constant pressure some work is to be due to displacement of piston whereas in constant volume the piston remains in its same place, therefore, no work is done.
So, cp will greater than cv that's why it is greater than 1.
So, cp will greater than cv that's why it is greater than 1.
(1)
Arif alam said:
1 decade ago
At constant volume the heat is directly increase the temperature but at constant pressure heat is given to the system then temp is increased and also expand so some heat is extra needed.
Satz said:
1 decade ago
W = Pdv in constant volume process work done is 0 and only increasing the internal energy but in constant pressure process internal energy increase and work also done on the system.
Arjun said:
1 decade ago
cp/cv or Y always greater than 1.
Monoatomic gases Y = 5/3 like cr, ne, he.
Diatomic Y = 7/5 or 1.4 like o2, n2, h2.
Triatomic or polyatomic Y = 4/3 or 1.33 like so2, co2.
Monoatomic gases Y = 5/3 like cr, ne, he.
Diatomic Y = 7/5 or 1.4 like o2, n2, h2.
Triatomic or polyatomic Y = 4/3 or 1.33 like so2, co2.
Yosef mulugeta said:
1 decade ago
cp/cv = 5/3 = 1.6 this for monoatomic particle.
cp/cv = 7/5 = 1.4 this for diatomic particle.
So, cp/cv = R where, R is molar mass.
R>1.
cp/cv = 7/5 = 1.4 this for diatomic particle.
So, cp/cv = R where, R is molar mass.
R>1.
Ashiq said:
9 years ago
I have a doubt, the ratio of specific of gas at a constant pressure and constant volume is constant or varying.
(1)
Mandar said:
1 decade ago
It is given that the ratio of cp/cv=R which is consatant and value is 1.14 which is constant.
Anik Babu said:
9 years ago
Why it is 1.33 and 1.40?
I have answer for 1.67 but not for those. Will anyone explain me?
I have answer for 1.67 but not for those. Will anyone explain me?
(1)
Prasad said:
1 decade ago
@Ambika: The above said is for gas. And it varies with the medium and composition.
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