The efficiency of a Carnot engine operating between temperatures of 100oC and -23oC will be
In a adiabatic process, the state of a gas is changed from P1, V1, T1 to P2, V2, T2. Which of the following relations is correct ?
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
The PT diagram for an ideal gas is shown in the figure, where AC is an adiabatic process. Find the corresponding PV diagram.
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
The efficiency of Carnot engine is 50% and temperature of sink is 500 K. If the temperature of source is kept constant and its efficiency is to be raised to 60%, then the required temperature of the sink will be
600 K
500 K
400 K
100 K
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
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
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
