Thermodynamics CBSE Questions & Answers

Thermodynamics

This is Physics Class 11 Thermodynamics CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

The picture of heat as a fluid was discarded in favor of the modern concept of heat as a form of energy because

A
Count Rumford observed that boring of brass cannon generated a lot of noise
B
Count Rumford observed that boring of brass cannon generated a lot of dust
C
Count Rumford observed that boring of brass cannon generated a lot of smoke
D
Count Rumford observed that boring of brass cannon generated a lot of heat
Correct

Thermodynamics is the branch of physics that deals with.

A
the concepts of heat and temperature and the inter-conversion of heat and other forms of energy
Correct
B
the concepts of kinetic energy and temperature and the inter-conversion of mechanical and other forms of energy
C
the concepts of heat and dust and the inter-conversion of heat and other forms of matter
D
the concepts of heat and noise and the inter-conversion of noise and other forms of energy

Thermodynamic state of a system is an equilibrium state

A
if the macroscopic variables that characterize the system change randomly
B
if the macroscopic variables that characterize the system do not change in time
Correct
C
if the macroscopic variables that characterize the system change linearly in time
D
if the macroscopic variables that characterize the system change decrease in time

Adiabatic wall is –

A
a thermally insulating wall that does allows flow of heat from one body to another
B
a thermally conducting wall that does not allow flow of heat from one body to many
C
a thermally conducting wall that does not allow flow of heat from one body to another
D
a thermally insulating wall that does not allow flow of heat from one body to another
Correct

Diathermic wall is

A
a thermally insulating wall that does not allow flow of heat from one body to many
B
a thermally conducting wall that does not allow flow of heat from one body to another
C
a thermally insulating wall that allows flow of heat from one body to another
D
a thermally conducting wall that allows flow of heat from one body to another
Correct

Zeroth Law of Thermodynamics

A
states that two systems in thermal equilibrium with a third system simultaneously are never in thermal equilibrium with each other
B
states that a system in thermal equilibrium with a third system separately is in thermal equilibrium with any other
C
states that two systems in thermal equilibrium with a third system separately are in thermal equilibrium with each other
Correct
D
states that two systems in thermal equilibrium with a third system separately cannot be in thermal equilibrium with each other

Internal energy of a system

A
is the difference of the kinetic energies and potential energies of the molecules of the system
B
is the change in the sum of the kinetic energies and potential energies of the molecules of the system
C
is the sum of the kinetic energies and potential energies of the molecules of the system
Correct
D
is the change in the difference of the kinetic energies and potential energies of the molecules of the system

Internal energy of a system is

A
a random variable
B
a complex variable
C
a discrete variable
D
a state variable
Correct

First Law of Thermodynamics is

A
the general law of conservation of mass applied to any system in which the energy transfer from or to the surroundings is taken into account
B
the general law of conservation of angular momentum applied to any system in which the energy transfer from or to the surroundings is taken into account
C
the general law of conservation of energy applied to any system in which the energy transfer from or to the surroundings is taken into account
Correct
D
the general law of conservation of momentum applied to any system in which the energy transfer from or to the surroundings is taken into account

If \(\Delta \)Q is the energy supplied to the system \(\Delta \)U the change in internal energy, and \(\Delta \)W the work done on the environment, First Law of Thermodynamics states that

A
\(\Delta \)U + \(\Delta \)W = 0
B
\(\Delta \)Q = \(\Delta \)U \( \times \) \(\Delta \)W
C
\(\Delta \)Q = \(\Delta \)U - \(\Delta \)W
D
\(\Delta \)Q = \(\Delta \)U + \(\Delta \)W
Correct

For solids near room temperature the molar specific heat (R is the universal gas constant)

A
R
B
5R
C
3R
Correct
D
2R

If \({{\rm{C}}_{\rm{p}}}\) and \({{\rm{C}}_{\rm{v}}}\) are molar specific heat capacities of an ideal gas at constant pressure and volume respectively and R is the universal gas constant, relation between the three is

A
\({{\rm{C}}_{\rm{p}}}\) - \({{\rm{C}}_{\rm{v}}}\) = R
Correct
B
\({{\rm{C}}_{\rm{p}}}\) + \({{\rm{C}}_{\rm{v}}}\) = 2R
C
\({{\rm{C}}_{\rm{p}}}\) + \({{\rm{C}}_{\rm{v}}}\) = R
D
\({{\rm{C}}_{\rm{p}}}\) - \({{\rm{C}}_{\rm{v}}}\) = 2R

In Thermodynamics Extensive variables depend

A
on the ‘size’ of the system
Correct
B
on the ‘pressure’ of the system
C
on the ‘temperature’ of the system
D
on the ‘entropy’ of the system

If pressure and volume of an ideal gas change the work done by the gas is given by

A
P \(\Delta \)V
Correct
B
P / \(\Delta \)V
C
P - \(\Delta \)V
D
P + \(\Delta \)V

In a quasi-static process,

A
the temperature of the surrounding reservoir and the external pressure differ substantially from the temperature and pressure of the system
B
the temperature of the surrounding reservoir and the external pressure equal the temperature and pressure of the system
C
the temperature of the surrounding reservoir and the external pressure differ only infinitesimally from the temperature and pressure of the system
Correct
D
the temperature of the surrounding reservoir differ only infinitesimally from the temperature of the system