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
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
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
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 ?
Which of the following statement is correct for any thermodynamic system ?
The internal energy changes in all processes
Internal energy and entopy are state functions
The change in entropy can never be zero
The work done in an adiabatic process is always zero.
The efficiency of a Carnot engine operating between temperatures of 100oC and -23oC will be
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
P-V plots for two gases during an adiabatic processes are shown in figure. Plots 1 and 2 should correspond respectively to
He and O2
O2 and He
He and Ar
O2 and N2
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
An ideal mono atomic gas is taken around the cycle ABCDA as shown in the PV diagram. The work done during the cycle is given by
1/2 PV
PV
2 PV
4 PV
