Description : In polytropic process (PV n = constant), if n = 1; it means a/an __________ process. (A) Adiabatic (B) Reversible (C) Isothermal (D) None of these
Last Answer : (C) Isothermal
Description : Which of the following processes are thermodynamically reversible (a) throttling (b) free expansion (c) constant volume and constant pressure (d) hyperbolic and pV = C (e) isothermal and adiabatic.
Last Answer : Answer : e
Description : On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line ... Y (C) (∂P/∂V)S = y(∂P/∂V)T (D) (∂P/∂V)S = 1/y(∂P/∂V)T
Last Answer : (C) (∂P/∂V)S = y(∂P/∂V)T
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 : 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 : 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 : What happens in a reversible adiabatic expansion process? (A) Heating takes place (B) Cooling takes place (C) Pressure is constant (D) Temperature is constant
Last Answer : (B) Cooling takes place
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 : 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 : Pick out the wrong statement: (A) The expansion of a gas in vacuum is an irreversible process (B) An isometric process is a constant pressure process (C) Entropy change for a reversible adiabatic process is zero (D) Free energy change for a spontaneous process is negative
Last Answer : (B) An isometric process is a constant pressure process
Description : Pick out the wrong statement. (A) The net change in entropy in any reversible cycle is always zero (B) The entropy of the system as a whole in an irreversible process increases (C) The ... to a maximum (D) The entropy of a substance does not remain constant during a reversible adiabatic change
Last Answer : (D) The entropy of a substance does not remain constant during a reversible adiabatic change
Description : In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process. (A) Isothermal (B) Isobaric (C) Polytropic (D) Adiabatic
Last Answer : (A) Isothermal
Description : Charles' law for gases states that (A) V/T = Constant (B) V ∝ 1/T (C) V ∝ 1/P (D) PV/T = Constant
Last Answer : (A) V/T = Constant
Description : Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas (Y = Cp/Cv = 7/5) and the process to be reversible, is (A) 300 × (32/7) (B) 300 × (33/5) (C) 300 × (333/7) (D) 300 × (35/7)
Last Answer : A) 300 × (32/7)
Description : Adiabatic process is (A) Essentially an isentropic process is___________ (B) Non-heat transfer process (C) Reversible process (D) Constant temperature process
Last Answer : (B) Non-heat transfer process
Description : The compressibility factor, x, is used for predicting the behavior of nonideal gases. How is the compressibility ty factor defined relative to an ideal gas? (subscript c refers to critical value) A. ... compressibility factor, x, is an dimensionless constant given by pV=zRT. Therefore z = pV / RT
Last Answer : z = pV/ RT
Description : Entropy of a substance remains constant during a/an __________ change. (A) Reversible isothermal (B) Irreversible isothermal (C) Reversible adiabatic (D) None of these
Last Answer : (C) Reversible adiabatic
Description : What happens in a reversible adiabatic compression? (A) Heating occurs (B) Cooling occurs (C) Pressure is constant (D) Temperature is constant
Last Answer : A) Heating occurs
Description : Work done may be calculated by the expression ∫ p dA for __________ processes. (A) Non-flow reversible (B) Adiabatic (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : he gas law (PV = RT) is true for an __________ change. (A) Isothermal (B) Adiabatic (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : When a gas in a vessel expands, its internal energy decreases. The process involved is (A) Reversible (B) Irreversible (C) Isothermal (D) Adiabatic
Last Answer : (A) Reversible
Description : Specific heat of a gas for a reversible adiabatic process is (A) Negative (B) Zero (C) Infinity (D) None of these
Last Answer : (B) Zero
Description : Entropy change in case of reversible adiabatic process is (A) Minimum (B) Zero (C) Maximum (D) Indeterminate
Description : 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
Last Answer : (B) Isothermal
Description : Which of the following non-flow reversible compression processes require maximum work? (A) Adiabatic process (B) Isothermal process (C) Isobaric process (D) All require same work
Last Answer : (A) Adiabatic process
Description : Pick out the correct statement: (A) In an isothermal system, irreversible work is more than reversible work (B) Under reversible conditions, the adiabatic work is less than isothermal work (C) ... state functions' (D) Matter and energy cannot be exchanged with the surroundings in a closed system
Last Answer : (B) Under reversible conditions, the adiabatic work is less than isothermal work
Description : An ideal gas of volume 1liter and pressure 10 bar undergoes a quasistatic adiabatic expansion until the pressure drops to 1 bar. Assume γ to be 1.4 what is the final volume? a. 3.18 l b. 4.18 l c. 5.18 l d. 6.18 l
Last Answer : 5.18 l
Description : For a reversible process involving only pressure-volume work (A) (dF)T, p < 0 (B) (dF)T, p > 0 (C) (dF)T, p = 0 (D) (dA)T, v < 0
Last Answer : (C) (dF)T, p = 0
Description : Entropy change for an adiabatic reversible process is
Last Answer : Entropy change for an adiabatic reversible process is A. Positive B. Zero C. Negative D. Constant
Description : Why entropy change for a reversible adiabatic process is zero ?
Last Answer : Because there is no heat transfer in this process.
Description : When the expansion of compression of gas takes place without transfer of heat to or from the gas the process is called a. reversible b. adiabatic c. polytropic d. isothermal
Last Answer : adiabatic
Description : Another name of reversible adiabatic process a. Isentropic Process b. Isometric Process c. Isobaric Process d. Isothermal Process
Last Answer : Isentropic Process
Description : During adiabatic, internally reversible process, what is true about the change in entropy? A. It is temperature-dependent B. It is always greater than zero C. It is always zero D. It is always less than zero
Last Answer : It is always zero
Description : The term “isentropic process” used in thermodynamics implies what? A. Reversible adiabatic process B. Externally reversible, adiabatic process C. Internally reversible, adiabatic process D. Irreversible adiabatic process
Last Answer : Internally reversible, adiabatic process
Description : “A reversible adiabatic process is necessarily isentropic but an isentropic process is not necessarily reversible adiabatic process.” This statement is: A. True B. False C. May be true and may be false D. Absurd
Last Answer : True
Description : How does an adiabatic process compare to an isentropic process? A. Adiabatic heat transfer is not equal to zero; isentropic heat transfer is zero B. Both heat transfer = 0; isentropic: reversible ... is not equal to zero D. Both heat transfer is not equal to zero; isentropic: irreversible
Last Answer : Both heat transfer = 0; isentropic: reversible
Description : For reversible adiabatic process, change in entropy is (a) maximum (b) minimum (c) zero (d) unpredictable (e) negative
Last Answer : Answer : c
Description : The value of n = 1 in the polytropic process indicates it to be (a) reversible process (b) isothermal process (c) adiabatic process (d) irreversible process (e) free expansion process.
Last Answer : Answer : b
Description : 3.0 lbm of air are contained at 25 psia and 100 ˚F. Given that Rair = 53.35 ft-lbf/lbm- ˚F, what is the volume of the container? A.10.7 ft^3 B.14.7 ft^3 C.15 ft^3 D.24.9 ft^3 Formula: use the ideal gas law pV = mRT T = (100 +460) ˚R V = mRT/p
Last Answer : 24.9 ft^3
Description : If air is at pressure, p, of 3200 lbf/ft2 , and at a temperature, T, of 800 ˚R, what is the specific volume, v? (R=5303 ft-lbf/lbm-˚R, and air can be modeled as an ideal gas.) A.9.8 ft^3/lbm B.11.2 ft^3/lbm C.13.33 ft^3/lbm D.14.2 ft^3/lbm Formula: pv = RT v = RT / p
Last Answer : 13.33 ft^3/lbm
Description : Which of the following is the Ideal gas law (equation)? A. V/T = K B. V= k*(1/P) C. P1/T1 = P2/T2 D. PV = nRT
Last Answer : PV = nRT
Description : if pressure P is inversely proportional to volume (V) at constant temperature, then PV is constant (True/False)
Last Answer : if pressure P is inversely proportional to volume (V) at constant temperature, then PV is constant (True/False)
Description : Represent Isobaric, Isochoric, Isothermal, Adiabatic process on P-V and T-S diagram.
Last Answer : Isobaric process Isothermal process Isochoric process Adiabatic process:
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 case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v23 m3) is maximum, when the value of 'n' is (A) 0 (B) 1 (C) y = 1.44 (D) 1.66
Last Answer : (A) 0
Description : The energy equation, E + (p/ρ) + (V 2 /2g) + gZ = constant (E = internal energy/mass), is applicable to (A) Perfect gases only (B) Isothermal flow of gases (C) Adiabatic unsteady flow of gases (D) All compressible fluids
Last Answer : (D) All compressible fluids
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
Last Answer : Answer : a
Description : Represent constant volume process on PV & TS diagram for steam.
Last Answer : Represent constant volume process on PV & TS diagram for steam.
Description : Generation of heat by friction is an example of a/an __________ change. (A) Isothermal (B) Irreversible (C) Adiabatic (D) Reversible
Last Answer : (B) Irreversible
Description : Stirling and Ericsson cycles are (a) reversible cycles (b) irreversible cycles (c) quasi-static cycles (d) semi-reversible cycles (e) adiabatic irreversible cycles.