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
Initial pressure and volume of a gas are P and V respectively. First the gas is expanded isothermally to 4V and then its volume is made V by adiabatic process. Its final pressure (γ = 1.5) is
8 P
4 P
P
2 P
Which one of the following is not a state function ?
temperature
entropy
pressure
work
First law of thermodynamics is a consequence of conservation of
Work
Energy
Heat
All of these
The temperature of source and sink of a heat engine are 127oC and 27oC respectively. An inventor claims its efficiency to be 26%, then
It is impossible
It is possible with high probability
It is possible with low probability
Data are insufficient
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
A Carnot engine, having an efficiency of 1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is
1 J
90 J
99 J
100 J
One mole of a mono atomic gas is heated at a constant pressure of 1 atmosphere from 0 K to 100 K. If the gas constant R = 8.32J/mol K, the change in internal energy of the gas is approximately.
2.3 J
46 J
8.67 x 103 J
1.25 x 103 J
Which of the following is incorrect regarding the first law of thermodynamics ?
It introduces the concept of the internal energy
It introduces the concept of the entropy
It is not applicable to any cyclic process
It is restatement of the principle of conservation of energy
Universal gas constant is
CP - CV
CP + CV
