Thermodynamics Questions and Answers – Energy Equation-1

This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on “Energy Equation-1”.

1. For a system which undergoes an infinitesimal reversible process between two equilibrium states, the change in internal energy is
a) dU = pdV – TdS
b) dU = TdS + pdV
c) dU = TdS – pdV
d) dU = -TdS – pdV
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2. The energy equation is given by
a) (∂U/∂V) = T*(∂p/∂T) + p
b) (∂U/∂V) = T*(∂p/∂T) – p
c) (∂U/∂V) = -T*(∂p/∂T) – p
d) (∂U/∂V) = p – T*(∂p/∂T)
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3. If temperature is constant, internal energy does not change.
a) true
b) false
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4. If the temperature is constant, internal energy
a) changes with change in p
b) changes with change in V
c) changes with change in both p and V
d) does not change with change in p or V
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5. The equation dU=Cv*dT holds good for
a) any process for an ideal gas, even when the volume changes
b) for other substances it is true only when the volume is constant
c) both of the mentioned
d) none of the mentioned
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6. Thermal radiation in equilibrium with enclosing walls possesses an energy that depends on volume and temperature.
a) true
b) false
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7. If the temperature is constant, enthaply
a) changes with change in p
b) changes with change in V
c) changes with change in both p and V
d) does not change with change in p or V
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8. The equation dH=Cp*dT holds good for
a) any process for an ideal gas, even when the pressure changes
b) for other substances it is true only when the pressure is constant
c) both of the mentioned
d) none of the mentioned
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9. If u is the energy density then pressure(p) exerted by the black-body radiation in an enclosure is
a) u/2
b) u/3
c) u/4
d) u
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10. The Stefan-Boltzmann law is given by
a) u = b*(T²)
b) u = b*(T³)
c) u = b*(T⁴)
d) u = b*T
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11. For a reversible isothermal change of volume, heat to be supplied reversibly to keep temperature constant is given by
a) Q = (4/3)b*(T⁴)*(ΔV)
b) Q = (2/3)b*(T²)*(ΔV)
c) Q = (1/3)b*(T)*(ΔV)
d) none of the mentioned
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12. If the temperature is half the original temperature, the volume of black-body radiation is to be ____ adiabatically ____ times its original volume for radiation to remain at equilibrium.
a) decreased, four
b) decreased, eight
c) increased, four
d) increased, eight
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Sanfoundry Global Education & Learning Series – Thermodynamics.
To practice all areas of Thermodynamics, here is complete set of 1000+ Multiple Choice Questions and Answers.

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