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

Related Mcqs:

1. 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...

2. 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...

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

   A. Simultaneous pressure & temperature change B. Heating C. Cooling D. Both B. and C...

4. 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...

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. 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...

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

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

8. A change in state involving a decrease in entropy can be spontaneous, only if ____________________?

   A. It is exothermic B. It is isenthalpic C. It takes place isothermally D. It takes place at constant volume...

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

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

10. The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is_________________?

    A. R loge 4 B. R log10 4 C. Cv log10 4 D. Cv loge 4...