CBSE
Multiple Choice QuestionsA lead bullet penetrates into a solid object and melts. Assuming that 50% of its kinetic energy was used to heat it, the initial speed of the bullet is (the initial temperature of the bullet is 25oC and its melting point is 300°C). Latent heat of fusion of lead= 2.5 x 104 J/kg and specific heat capacity of lead= 125 J/kg-K
100 m/s
≈ 490 m/s
520 m/s
360 m/s
3 mole of hydrogen is mixed with 1 mole of neon. The molar specific heat at constant pressure is
The slope of isothermal and adiabatic curves are related as
isothermal curve slope= adiabatic curve slope
isothermal curve slope = γ × adiabatic curve slope
adiabatic curve slope = γ× isothermal curve slope
adiabatic curve slope =× isothermal curve slope
A Carnot engine operates with source at 127°C and sink at 27°C. If the source supplies 40 kJ of heat energy, the work done by the engine is
30 kJ
10 kJ
4 kJ
1 kJ
When an ideal monoatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas is
2 / 5
3 / 5
3 / 7
5 / 7
Assertion: It is not possible for a system, unaided by an external agency to transfer heat from a body at lower temperature to another body at a higher temperature.
Reason: It is not possible to violate the second law of thermodynamics
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: The specific heat of a gas in an adiabatic process is zero and in an isothermal process is infinite.
Reason: Specific heat of gas is directly proportional to change of heat in system and inversely proportional to change in temperature.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: In an isolated system the entropy increases.
Reason: The process in an isolated system is adiabatic only.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
The volume of an ideal gas is doubled in an isothermal process. Then, which of the following is true?
Work done by the gas is positive
Work done by the gas is negative
Internal energy of the system decreases
Internal energy of the system increases
A thermodynamic process is carried out from an original state D to an intermediate state E by the linear process shown in figure
The total work is done by the gas from D to E to F is
100 J
800 J
300 J
250 J
