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
An ideal gas initially at P1, V1 is expanded to P2, V2 and then compressed adiabatically to the same volume V1 and pressure P3. If W is the net work done by the gas in complete process, which of the following is true ?
W > 0 ; P3 > P1
W < 0 ; P3 > P1
W > 0 ; P3 < P1
One mole of an ideal gas at an initial temperature of T K does 6R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 5/3, the final temperature of gas will be
(T + 2.4)K
(T - 2.4)K
(T + 4)K
(T - 4)K
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 ?
The PT diagram for an ideal gas is shown in the figure, where AC is an adiabatic process. Find the corresponding PV diagram.
The efficiency of a Carnot engine operating between temperatures of 100oC and -23oC will be
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
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
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
5.6 litre of helium gas at STP is adiabatically compressed to 0.7 litre. Taking the initial temperature to be T1, the work done in the process is
