The expression for entropy change, ΔS = n Cp . ln (T2/T1), is valid for the ______________ of a substance?

Related Mcqs:

1. The expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for ______________________?

   A. Reversible isothermal volume change B. Heating of a substance C. Cooling of a substance D. Simultaneous heating and expansion of an ideal gas...

2. Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is_______________?

   A. Superheated vapour B. Partially condensed vapour with quality of 0.9 C. Saturated vapour D. Partially condensed vapour with quality of 0.1...

3. The expression for entropy change given by, ΔS = – nR ln (P2/P1), holds good for___________________?

   A. Expansion of a real gas B. Reversible isothermal volume change C. Heating of an ideal gas D. Cooling of a real gas...

4. Entropy of a substance remains constant during a/an ____________ change?

   A. Reversible isothermal B. Irreversible isothermal C. Reversible adiabatic D. None of these...

5. High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process ?

   A. Δ H = 0 and ΔS = 0 B. Δ H ≠ 0 and ΔS = 0 C. Δ H ≠ 0 and ΔS ≠ 0 D. Δ H = 0 and ΔS ≠ 0...

6. “At the absolute zero temperature, the entropy of every perfectly crystalline substance becomes zero”. This follows from the __________________?

   A. Third law of thermodynamics B. Second law of thermodynamics C. Nernst heat theorem D. Maxwell’s relations...

7. The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible _____________ process?

   A. Isobaric B. Isothermal C. Adiabatic D. None of these...

8. Entropy change for an irreversible process taking system and surrounding together is___________________?

   A. 0 B. > 0 C. < 0 D. None of these...

9. A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively) ?

   A. Δ S1 is always Δ SR C. Δ S1 is always > Δ SR D. Δ S1 is always = Δ SR...

10. Entropy change in case of reversible adiabatic process is________________?

    A. Minimum B. Zero C. Maximum D. Indeterminate...