A. < 0
B. > 0
C. = 0
D. None of these
Related Mcqs:
- 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 - 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 - A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1 is_________________?
A. -1.87
B. 0
C. 1.26
D. 3.91 - “When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change.” This is called the_______________?
A. Le-Chatelier principle
B. Kopp’s rule
C. Law of corresponding state
D. Arrhenius hypothesis - Entropy change for an irreversible isolated system is__________________?
A. ∞
B. 0
C. < 0
D. > 0 - 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 - A system is said to be at equilibrium, if the entropy of the system has reached ____________ value?
A. Minimum
B. Zero
C. Maximum
D. None of these - 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 - Entropy change for an irreversible process taking system and surrounding together is___________________?
A. 0
B. > 0
C. < 0
D. None of these - Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of___________________?
A. Solution
B. Vaporisation
C. Formation
D. Sublimation
