| 1 |
The efficiency of carnot engine cannot be 100% or one unless cold reservoir is at
|
A. 100 K
B. 273 K
C. 0 K
D. -273 K
|
| 2 |
In an adiabatic expansion, the temperature of the gas
|
A. increases
B. becomes zero
C. decreases
D. decreases rapidly
|
| 3 |
Which quantity is important in stating the entropy of the system
|
A. initial entropy
B. final entropy
C. change in entropy
D. none of them
|
| 4 |
At O° K which of the following properties of a gas will be zero?
|
A. Kinetic energy
B. Potential energy
C. Vibrational energy
D. Density
|
| 5 |
The bicycle pump provides a good example of
|
A. first law of thermodynamics
B. second law of thermodynamics
C. third law of thermodynamics
D. none of them
|
| 6 |
According to the second law, which is must to produce work
|
A. a source contains a large amount of heat energy
B. two sources at the same temperature
C. two sources at the different temperatures
D. a source contains a small amount of energy
|
| 7 |
If a molecule with momentum mv strikes a wall and rebound then the change in momentum will be:
|
A. -2 mv
B. Zero
C. 2 mv
D. mv
|
| 8 |
Pressure exerted by a gas is
|
A. Independent of density of the gas
B. Inversely proportional to the density of the gas
C. Directly proportional to the square of the density of the gas
D. Directly proportional to the density of the gas
|
| 9 |
When two objects are rubbed together, their internal energy
|
A. remains same
B. decreases
C. remains the same then decreases
D. increases
|
| 10 |
The curve representing an isothermal process is called
|
A. adiabat
B. isotherm
C. fixed temperature
D. none of them
|
| 11 |
If the formula PV = nRT, n denotes:
|
A. Number of molecules per unit volume
B. Number of moles
C. Number of molecules
D. None of these
|
| 12 |
Efficiency of carnot engine is independent of the
|
A. temperature of sink
B. temperature of source
C. nature of the working substances
D. none of them
|
| 13 |
On the power stroke, a spark fires the mixtures causing a rapid increase in pressure and temperature and the burning mixture expands
|
A. adiabatically
B. isothermally
C. isochorically
D. isobarically
|
| 14 |
Carnot heat engine only used
|
A. isothermal processes
B. adiabatic processes
C. both of them
D. none of them
|
| 15 |
The volume of given mass of a gas will be doubled at atmosphere pressure if the temperature of the gas is changed from 150°C to
|
A. 300°C
B. 573°C
C. 600°C
D. 743°C
|
| 16 |
If the ratio of densities of two gases is 1:4, then the ratio of their rates of diffusion into one another is
|
A. 2 : 1
B. 4 : 1
C. 1 : 4
D. 3 : 4
|
| 17 |
First law of thermodynamics tells us that heat energy can be converted into equivalent amount of work, but it is silent about
|
A. how heat is absorbed
B. how heat extracted
C. how this conversion takes place
D. none of them
|
| 18 |
The internal energy of a system does not depend upon the
|
A. initial state of the system
B. final state of the system
C. path
D. none of them
|
| 19 |
Truth of kinetic energy is confirmed by:
|
A. Diffusion of gases
B. Brownian motion
C. Both A and B
D. None of these
|
| 20 |
The example of irreversible process is
|
A. slowly liquification
B. slowly evaporation
C. an explosion
D. all of them
|
| 21 |
At constant temperature, on increasing the pressure of a gas by 5%, its volume. The final temperature of the gas will be
|
A. 81 K
B. 355 K
C. 627 K
D. 627°C
|
| 22 |
If R is gas constant for 1 gram mole, Cpand Cvare specific heat for a solid then
|
A. Cp- Cv= R
B. Cp- Cv < R
C. Cp- Cv = 0
D. Cp- Cv > R
|
| 23 |
A real gas can be approximated to an ideal gas at
|
A. Low density
B. High pressure
C. High density
D. Low temperature
|
| 24 |
First law of thermodynamics is consequence of conservation of
|
A. Work
B. Energy
C. Heat
D. All of these
|
| 25 |
If the distance between two charges is doubled, the force between them will become:
|
A. Double
B. Half
C. Three times
D. One fourth
|
| 26 |
In all natural processes where heat flows from one system to another, there is always a net
|
A. decrease in entropy
B. increase in entropy
C. decrease or increase in entropy
D. none of them
|
| 27 |
During the whole carnot cycle
|
A. Thermal equilibrium is maintained
B. mechanical equilibrium is maintained
C. both the thermal and mechanical equilibriumis maintained
D. both the thermal and mechanical equilibrium is not maintained
|
| 28 |
The concept of entropy was introduced into the study of thermodynamics in
|
A. 1856
B. 1865
C. 1656
D. 1685
|
| 29 |
Pressure may be define as _______ per second per unit area:
|
A. Change in force
B. Change in momentum
C. Change in energy
D. Work done
|
| 30 |
Absolute temperature can be calculated by
|
A. Means squares velocity
B. Motion of the molecule
C. Both A and B
D. None of these
|