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 number of translational degree of freedom for a diatomic gas is:
2
3
5
6
1 g of water at atmospheric pressure has volume of 1 cm3 and when boiled it becomes 1681 cm3 of steam. The heat of vaporisation of water is 540 cal/g. Then the change in its internal energy in this process is :
540 cal
500 cal
1681 cal
none of these
"Heat cannot itself flow from a body at lower temperature to a body at higher temperature" is a statement related to:
Second law of thermodynamics
Conservation of momentum
Conservation of mass
First law of thermodynamics
The volume (V) versus temperature (T) graphs for a certain amount of a perfect gas at two pressures P1 and P2are shown in the figure. It follows from the graph :
P1 > P2
P1 < P2
P1 = P2
information is insufficient to draw any conclusion.
First law of thermodynamics is a consequence of conservation of:
Work
Energy
Heat
All of these
P-V plots for two gases during 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
100 g of water is heated from 30oC to 50oC. Ignoring the slight expansion of the water, the change in its internal energy is (specific heat of water is 4184 J/kg/K)
4.2 kJ
8.4 kJ
84 kJ
2.1 kJ
Which of the following parameters does not characterize the thermodynamic state of matter ?
Temperature
Pressure
Volume
A Carnot engine operating between temperatures T1 and T2 has efficiency 1/6. When T2 is lowered by 62 K, its efficiency increases to 1/3. Then T1 and T2 are, respectivley :
372 K and 310 K
372 K and 330 K
330 K and 268 K
310 K and 248 K
