An ideal gas is taken through the cycle A B C A as shown in the figure. If the net heat supplied to the gas in the cycle is 5 J, the work done by the gas in the process C A is
- 5 J
- 10 J
- 15 J
- 20 J
The internal energy change in a system that has absorbed 2 kcal of heat and done 500 J of work is
8900 J
6400 J
5400 J
7900 J
In an adiabatic process, the state of a gas is changed from P1, V1, T1 to P2, V2, T2. Which of the following relations is correct ?
An ideal gas is compressed adiabatically to 8/27 times of its present value at 27oC. The temperature of the gas becomes (γ= 5/3).
475oC
275oC
402oC
175oC
Which of the following parameters does not characterize the thermodynamic state of matter ?
Temperature
Pressure
Work
Volume
The temperature-entropy diagram of a reversible engine cycle is given in the figure. Its efficiency is
1/3
1/2
2/3
1/4
"Heat cannot itself flow from a body at lower temperature to a body at higher temperature" is a statement or consequence of
second law of thermodynamics
conservation of momentum
conservation of mass
first law of thermodynamics
A scientist says that the efficiency of his heat engine which works at source temperature of 127oC and sink temperature 27oC is 26%.
It is impossible
It is possible but less probable
It is quite possible
Data is incomplete
If cp and cv denote the specific heat of nitrogen per unit mass at constant pressure and constant volume respectively, then
cp - cv = R/28
cp - cv = R/14
cp - cv = R
cp - cv = 28R
A gas at state A changes to state B through path I and II shown in figure. The changes in internal energy are ΔU1 and ΔU2 respectively. Then
Δ U1 > ΔU2
Δ U1 < ΔU2
Δ U1 = ΔU2
Δ U1 = ΔU2 = 0