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 : For reversible adiabatic process, change in entropy is (a) maximum (b) minimum (c) zero (d) unpredictable (e) negative
Last Answer : Answer : c
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 : Entropy change in case of reversible adiabatic process is (A) Minimum (B) Zero (C) Maximum (D) Indeterminate
Last Answer : (B) Zero
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 : 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 : During the adiabatic process, which of the following is the change in entropy? a. zero b. greater than zero c. less than zero d. infinity
Last Answer : zero
Description : For a thermodynamic process to be reversible, the temperature difference between hot body and working substance should be (a) zero (b) minimum (d) maximum (d) infinity (e) there is no such criterion.
Last Answer : Answer : a
Description : Why entropy change for a reversible adiabatic process is zero ?
Last Answer : Because there is no heat transfer in this 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 : 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 : 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 : 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 : 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 : Which of the following is not correct for a reversible adiabatic process? (A) TV γ-1 = constant (B) p 1-γ .T Y = constant (C) PV γ = constant (D) None of these
Last Answer : (D) None of these
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 : 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 : 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 : 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 = 1, then it represents a reversible __________ process. (A) Isothermal (B) Isobaric (C) Polytropic (D) Adiabatic
Last Answer : (A) 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 : 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 : Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature ... release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The work done in an adiabatic change in a particular gas depends upon changes in the __________ only. (A) Temperature (B) Specific heat (C) Volume (D) Pressure
Last Answer : (A) Temperature
Description : What is the value of ln y (where y = activity co-efficient) for ideal gases? (A) Zero (B) Unity (C) Infinity (D) Negative
Last Answer : (A) Zero
Description : Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is (A) Positive (B) Negative (C) Zero (D) Infinity
Last Answer : C) Zero
Description : At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is (A) Zero (B) One (C) Infinity (D) Negative
Last Answer : (B) One
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 : Another name of reversible adiabatic process a. Isentropic Process b. Isometric Process c. Isobaric Process d. Isothermal Process
Last Answer : Isentropic Process
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 : 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 : The second law of thermodynamics states that (A) The energy change of a system undergoing any reversible process is zero (B) It is not possible to transfer heat from a lower temperature to a higher temperature (C) The total energy of system and surrounding remains the same (D) None of the above
Last Answer : (D) None of the above
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 : Adiabatic bulk modulus is equal to: A. Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure B. Pressure C. The ratio of the specific heat capacities of the gas D. Υ ⁄ P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure
Last Answer : Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressur
Description : The focal length of a plane mirror is (1) Positive (2) Negative (3) Zero (4) Infinity
Last Answer : (4) Infinity Explanation: A plane mirror is a mirror with a flat reflective surface. The focal length of a plane mirror is infinity. Its optical power is zero.
Description : When temperature rises, resistance of negative temperature coefficient thermistor A. increases B. decreases C. zero D. infinity
Last Answer : decreases
Description : Gravitational potential is always A. positive B. negative C. zero D. infinity
Last Answer : negative
Description : The conductivity in free space medium is a) Infinity b) Unity c) Zero d) Negative
Last Answer : c) Zero
Description : The magnetic susceptibility in a superconductor will be a) Positive b) Negative c) Zero d) Infinity
Last Answer : b) Negative
Description : The potential taken between two points across a resistor will be a) Positive b) Negative c) Zero d) Infinity
Description : . In a shell and tube heat exchanger, the tube side heat transfer coefficient just at the entrance of the tube is (A) Infinity (B) Zero (C) Same as average heat transfer co-efficient for tube side (D) None of these
Last Answer : (A) Infinity
Description : In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity
Last Answer : (C) Zero
Description : As the temperature is lowered towards the absolute zero, the value of ∂(∆F)/∂T, then approaches (A) Unity (B) Zero (C) That of the heat of reaction (D) Infinity
Last Answer : B) Zero
Description : Claude process of gas liquefaction employs (A) Merely compression of gas beyond its critical pressure (B) Joule-Thomson expansion cooling (C) Heat exchange with colder stream (D) Adiabatic expansion against a piston or in a turbine
Last Answer : (D) Adiabatic expansion against a piston or in a turbine