Description : A state occurs in isentropic process a. The change in entropy is 0 b. The change in entropy is 1 c. The change in enthalpy is 0 d. The change in enthalpy is 1
Last Answer : The change in entropy is 0
Description : Throttling (Joule-Thomson effect) process is a constant __________ process. (A) Enthalpy (B) Entropy (C) Pressure (D) None of these
Last Answer : (A) Enthalpy
Description : Specific __________ does not change during phase change at constant temperature and pressure. (A) Entropy (B) Gibbs energy (C) Internal energy (D) Enthalpy
Last Answer : (B) Gibbs energy
Description : Throttling process is a/an __________ process. (A) Reversible and isothermal (B) Irreversible and constant enthalpy (C) Reversible and constant entropy (D) Reversible and constant enthalpy
Last Answer : (B) Irreversible and constant enthalpy
Description : Joule-Thomson effect i.e., a throttling process is a constant __________ process. (A) Entropy (B) Temperature (C) Internal energy (D) Enthalpy
Last Answer : (D) Enthalpy
Description : A process during which entropy remains constant is called ______ process A. Isometric B. Isochoric C. Isobaric D. Isentropic
Last Answer : Isentropic
Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : a
Description : If value of n is infinitely large in a polytropic process pV” = C, then the process is known as constant (a) volume (b) pressure (c) temperature (d) enthalpy (e) entropy
Description : If a solid is compressed adiabatically in its elastic range, its __________ remains constant (A) Internal energy (B) Enthalpy (C) Entropy (D) Temperature
Last Answer : (C) Entropy
Description : Superheating of steam is done at constant (A) Enthalpy (B) Entropy (C) Pressure (D) Volume
Last Answer : Option C
Description : __________ decreases during adiabatic throttling of a perfect gas. (A) Entropy (B) Temperature (C) Enthalpy (D) Pressure
Last Answer : (D) Pressure
Description : For an incompressible fluid, the __________ is a function of both pressure as well as temperature. (A) Internal energy (B) Enthalpy (C) Entropy (D) All (A), (B) & (C)
Last Answer : (B) Enthalpy
Description : Vertical lines on pressure-enthalpy chart show constant (a) pressure lines (b) temperature lines (c) total heat lines (d) entropy lines
Last Answer : Ans: c
Description : On the pressure-enthalpy diagram, condensation and de-superheating is represented by a horizontal line because theprocess (a) takes place at constant pressure (b) takes place at constant temperature (c) takes place at constant entropy (d) takes place at constant enthalpy
Last Answer : Ans: a
Description : Short horizontal lines on pressure-enthalpy chart show (a) constant pressure lines (b) constant temperature lines (c) constant total heat lines (d) constant entropy lines
Description : What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.
Last Answer : Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.
Description : Change in enthalpy of a system is the heat supplied at (a) constant pressure (b) constant temperature (c) constant volume (d) constant entropy (e) N.T.P. condition.
Description : Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure (a) enthalpy (b) volume (c) mass (d) entropy (e) specific volume.
Last Answer : Answer : b
Description : Which of the following occurs in a reversible polytrophic process? a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Last Answer : Some heat transfer occurs
Description : According to first law of thermodynamics (a) work done by a system is equal to heat transferred by the system (b) total internal energy of a system during a process remains constant ( ... , enthalpy and entropy during a process remain constant (d) total energy of a system remains constant
Last Answer : Answer : d
Description : 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: ... (C) Δ H ≠ 0 and ΔS ≠ 0 (D) Δ H = 0 and ΔS ≠ 0
Last Answer : (B) Δ H ≠ 0 and ΔS = 0
Description : A thermodynamic process in which entropy is conserved a. isentropic b. adiabatic c. isothermal d. polytropic
Last Answer : isentropic
Description : During Joule-Thomson expansion of gases (A) Enthalpy remains constant (B) Entropy remains constant (C) Temperature remains constant (D) None of these
Last Answer : (A) Enthalpy remains constant
Description : Mollier chart is a __________ plot. (A) Pressure vs. enthalpy (B) Pressure vs. volume (C) Enthalpy vs. entropy (D) Temperature vs. entropy
Last Answer : (C) Enthalpy vs. entropy
Description : Isobaric process means a constant process. (A) Temperature (B) Pressure (C) Volume (D) Entropy
Last Answer : (B) Pressure
Description : PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process. (A) Isothermal (B) Isentropic (C) Isobaric (D) Adiabatic
Last Answer : (D) Adiabatic
Description : In the equation, PVn = constant, if the value of n = ± ∞, then it represents a reversible __________ process. (A) Adiabatic (B) Isometric (C) Isentropic (D) Isothermal
Last Answer : (B) Isometric
Description : In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process. (A) Isometric (B) Polytropic (C) Isentropic (D) Isobaric
Last Answer : (B) Polytropic
Description : In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process. (A) Isothermal (B) Adiabatic (C) Isentropic (D) Polytropic
Last Answer : (C) Isentropic
Description : In the equation, PVn = Constant, if the value of n = 0, then it represents a reversible __________ process. (A) Isobaric (B) Isothermal (C) Isentropic (D) Isometric
Last Answer : (A) Isobaric
Description : 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 ... vapour with quality of 0.9 (C) Saturated vapour (D) Partially condensed vapour with quality of 0.1
Last Answer : (A) Superheated vapour
Description : An isentropic process is carried out at constant (A) Volume (B) Pressure (C) Temperature (D) All (A), (B) and (C)
Last Answer : (A) Volume
Description : For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot? (A) Temperature - entropy (B) Temperature - pressure (C) Enthalpy - entropy
Last Answer : (A) Temperature - entropy
Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy
Last Answer : (D) Gibbs free energy
Description : What is the energy absorbed during chemical reaction under constant volume conditions? A. Entropy B. Ion exchange C. Enthalpy D. Enthalpy of reaction
Last Answer : Enthalpy
Description : Pick out the correct statement. (A) Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero (B) Melting of ice involves increase in enthalpy and ... of an ideal gas depends only on its pressure (D) Maximum work is done under reversible conditions
Last Answer : (D) Maximum work is done under reversible conditions
Description : The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be (A) 0.4 (B) 0.56 (C) 0.67 (D) 1.67
Last Answer : (A) 0.4
Description : A ______ is a flow in which the gas flow is adiabatic and frictionless and entropy change is zero. A. Isentropic flow B. Isobaric flow C. Steady flow D. Uniform flow
Last Answer : Isentropic flow
Description : It is a process during which the pressure remains constant a. Adiabatic b. Isentropic c. Isobaric d. Isotropic
Last Answer : Isobaric
Description : A heat exchange process in which the product of pressure and volume remains constant is known as (a) heat exchange process (b) throttling process (c) isentropic process (d) adiabatic process (e) hyperbolic process.
Last Answer : Answer : e
Description : The sum of internal energy (U) and the product of pressure and volume (p.v) is known as A. workdone B. entropy C. enthalpy D. none of these
Last Answer : Answer: C
Description : Which of the following is the property of a system (a) pressure and temperature (b) internal energy (c) volume and density (d) enthalpy and entropy (e) all of the above.
Description : What is defined as the sum of the system’s internal energy and the product of its pressure and volume? a. Entropy. b. Enthalpy. c. Free energy. d. Potential energy.
Last Answer : b. Enthalpy.
Description : An isentropic process is the one, in which (A) pv = constant (B) pv r= constant (C) pv r = constant, and process is reversible (D) None of these
Last Answer : (C) pv r = constant, and process is reversible
Description : PVy = constant, holds good for an isentropic process, which is (A) Reversible and isothermal (B) Isothermal and irreversible (C) Reversible and adiabatic (D) Adiabatic and irreversible
Last Answer : C) Reversible and adiabatic
Description : The change that the system that undergoes from one equilibrium state to another is known as a. oath b. process c. enthalpy change d. entropy change
Last Answer : process
Description : Regardless of the process, the change in enthalpy firm moles of ideal gas is a. Heat b. Enthalpy c. Entropy d. Density
Last Answer : Heat
Description : Enthalpy changes over a constant pressure path are always zero for __________ gas. (A) Any (B) A perfect (C) An easily liquefiable (D) A real
Last Answer : (B) A perfect
Description : Carnot cycle is also termed as the constant __________ cycle in thermodynamics. (A) Entropy (B) Pressure (C) Volume (D) Heat
Last Answer : Option D
Description : Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work. (A) Isothermal (B) Adiabatic (C) Isentropic (D) None of these
Last Answer : (A) Isothermal