Description : For an ideal liquid solution, which of the following is unity? (A) Activity (B) Fugacity (C) Activity co-efficient (D) Fugacity co-efficient
Last Answer : (C) Activity co-efficient
Description : Activity co-efficient is a measure of the (A) Departure from ideal solution behaviour (B) Departure of gas phase from ideal gas law (C) Vapour pressure of liquid (D) None of these
Last Answer : (A) Departure from ideal solution behaviour
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 : For an ideal gas, the activity co-efficient is (A) Directly proportional to pressure (B) Inversely proportional to pressure (C) Unity at all pressures (D) None of these
Last Answer : (C) Unity at all pressures
Description : Pick out the wrong statement. (A) Activity co-efficient is dimensionless. (B) In case of an ideal gas, the fugacity is equal to its pressure. (C) In a mixture of ideal gases, the fugacity of ... equal to the partial pressure of the component. (D) The fugacity co-efficient is zero for an ideal gas
Last Answer : (D) The fugacity co-efficient is zero for an ideal gas
Description : At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole ... respectively. Activity co-efficient of methanol is (A) 1.572 (B) 1.9398 (C) 3.389
Last Answer : (A) 1.572
Description : What is the value of Joule-Thomson co-efficient for an ideal gas? (A) +ve (B) -ve (C) 0 (D) ∞
Last Answer : (C) 0
Description : Partial molar free energy of an element A in solution is same as its (A) Chemical potential (B) Activity (C) Fugacity (D) Activity co-efficient
Last Answer : (A) Chemical potential
Description : In a homogeneous solution, the activity co-efficient of a component depends upon the (A) Pressure (B) Composition (C) Temperature (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The activity co-efficient of the solute in a dilute solution (A) Decreases with the increase of concentration of the solute (B) Increases with the increase of concentration of the solute (C) Remains constant (D) Is unity at infinite dilution
Last Answer : (C) Remains constant
Description : A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yiis the liquid activity co- ... and liquid composition xi only (D) Temperature, pressure, liquid composition xi and vapour composition yi
Last Answer : (C) Temperature, pressure and liquid composition xi only
Description : An ideal coolant for a nuclear reactor should (A) Be a good absorber of neutrons (B) Be capable of attaining high temperature, only when it is pressurised (C) Have high density, but low heat transfer co-efficient (D) Be free from radiation damage and non-corrosive
Last Answer : (D) Be free from radiation damage and non-corrosive
Description : The expression, nCv(T2- T1), is for the __________ of an ideal gas. (A) Work done under adiabatic condition (B) Co-efficient of thermal expansion (C) Compressibility (D) None of these
Last Answer : (A) Work done under adiabatic condition
Description : The expression, nRT ln(P1/P2), is for the __________of an ideal gas. (A) Compressibility (B) Work done under adiabatic condition (C) Work done under isothermal condition (D) Co-efficient of thermal expansion
Last Answer : C) Work done under isothermal condition
Description : Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ____with the increase of reduced temperature. (A) Decreases (B) Increases (C) Remains constant
Last Answer : (B) Increases
Description : ________ Equation predicts the activity co-efficient from experimental data. (A) Lewis-Randall (B) Margules (C) Van Laar (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : Which of the following equations is used for the prediction of activity co-efficient from experiments? (A) Van Laar equation (B) Margules equation (C) Wilson's equation (D) All (A), (B) and (C)
Description : Which of the following is not affected by temperature changes? (A) Fugacity (B) Activity co-efficient (C) Free energy (D) None of these
Last Answer : (D) None of these
Description : Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure. (A) Fugacity (B) Partial pressure (C) Activity co-efficient (D) All (A), (B), and (C)
Last Answer : (D) All (A), (B), and (C)
Description : Which of the following is affected by the temperature? (A) Fugacity (B) Activity co-efficient (C) Free energy (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1is the activity co-efficient of component 1, is (A) A . x22 (B) Ax1 (C) Ax2 (D) Ax12
Last Answer : (A) A . x22
Description : Dephosphorization of molten pig iron is favoured by (A) Oxidising and basic slag (B) Reducing and basic slag (C) High activity co-efficient of phosphorous in metal (D) Oxidising and neutral slag
Last Answer : Option B
Description : In an ideal solution, the activity of a component equals its (A) Mole fraction (B) Fugacity at the same temperature and pressure (C) Partial pressure (D) None of these
Last Answer : (A) Mole fraction
Description : The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by (A) Increasing the gas film co-efficient (B) Increasing the liquid film co-efficient (C) Increasing the total pressure (D) Decreasing the total pressure
Last Answer : (A) Increasing the gas film co-efficient
Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system
Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect
Description : Diffusion co-efficient of a metal in a solid solution depends upon its (A) Composition (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2 /sec. (A) 0.25 (B) 2.5 (C) 1.25 (D) 0.0025
Last Answer : (A) 0.25
Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000
Last Answer : (D) > 10000
Description : Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8 . Pr n , is not valid, if the value of (A) n = 0.4 is used for heating (B) n = 0.3 is used for cooling (C) Reynolds number for the flow involved is > 10000 (D) Reynolds number for the flow involved is < 2100
Last Answer : (D) Reynolds number for the flow involved is < 2100
Description : What is the value of co-efficient of discharge for square edged circular orifice (for β = 0.3 to 0.5)? (A) 0.61 - 0.63 (B) 0.5 - 0.75 (C) 0.75 - 0.90 (D) 0.35 - 0.55
Last Answer : (A) 0.61 - 0.63
Description : Pick out the wrong statement. (A) The shear stress at the pipe (dia = D, length = L) wall in case of laminar flow of Newtonian fluids is (D/4L). ∆p (B) In the equation, T. gc = k. ... to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids
Last Answer : (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids
Description : The co-efficient of discharge of an orificemeter is a function of (A) Reynolds number at the orifice (B) Ratio of orifice dia to pipe dia (C) Both (A) and (B) (D) None of the above parameters, and has a constant value of 0.61
Last Answer : (C) Both (A) and (B)
Description : The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is (A) ∞ (B) 1 (C) 0 (D) -ve
Description : Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is (A) 0 (B) ∞ (C) +ve (D) -ve
Last Answer : (A) 0
Description : The effectiveness factor for large value of Thiele modulus [L√(K/D1 )] of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm2 /second). (A) L √(K/D1 ) (B) 1/[L√(K/D1 )] (C) 1 (D) ∞
Last Answer : (B) 1/[L√(K/D1 )]
Description : Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is (A) 0.01 to 0.1 (B) 0.1 to 0.3 (C) 0.2 to 0.8 (D) 0.2 to 0.4
Last Answer : (C) 0.2 to 0.8
Description : Compressibility co-efficient for an absolutely compressible cake is (A) 0 (B) 1 (C) 0 to 1 (D) ∞
Last Answer : (B) 1
Description : Mass transfer co-efficient is directly proportional to DAB 0.5 , according to __________ theory. (A) Penetration (B) Surface renewal (C) Film (D) None of these
Last Answer : (A) Penetration
Description : The inside heat transfer co-efficient in case of turbulent flow of liquid in the tube side in a 1-2 shell and tube heat exchanger is increased by __________ times, when the number of tube passes is increased to 8. (A) 2 0.8 (B) 4 0.8 (C) 4 0.4 (D) 2 0.4
Last Answer : (B) 4 0.8
Description : A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0 ... that of the un-insulated steam pipe (D) Less than the steam pipe with 5 cms insulation
Last Answer : (B) Less than that of the un-insulated steam pipe
Description : The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a ... )R = 1.5; (COP)HP = 2.5 (D) (COP)R = (COP)HP = 2.5
Last Answer : (C) (COP)R = 1.5; (COP)HP = 2.5
Description : The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the ... temperature of the right face in °C is (A) 77.2 (B) 71.2 (C) 63.8 (D) 48.7
Last Answer : (D) 48.7
Description : . The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C ... from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175
Last Answer : (A) 165.4
Description : The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient ... pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8
Last Answer : (B) D-0.2
Description : The average heat transfer co-efficient over the entire length of the plate (ha ) and the local heat transfer co-efficient (hL ), in case of heat transfer over a flat plate in laminar zone is related as (A) ha = 0.8hL (B) ha = 2hL (C) ha = hL (D) ha = 5hL
Last Answer : (B) ha = 2hL
Description : For a laminar flow of fluid in a circular tube, 'h1 ' is the convective heat transfer co-efficient at velocity 'V1 '. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is (A) 1.26 h1 (B) 0.794 h1 (C) 0.574 h1 (D) 1.741 h1
Last Answer : (B) 0.794 h1
Description : The fluid jet discharging from a 2" diameter orifice has a diameter of 1.75" at its vena-contracta. The co-efficient of contraction is (A) 1.3 (B) 0.766 (C) 0.87 (D) None of these
Last Answer : (B) 0.766
Description : The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10 -6m2 /s). (A) 24000 (B) 24 (C) 0.24(D) 0.44
Last Answer : (D) 0.44
Description : What is the co-efficient of contraction, if a fluid jet discharging from a 50 mm diameter orifice has a 40 mm diameter at its vena-contracta? (A) 0.64 (B) 1.65 (C) 0.32 (D) 0.94
Last Answer : (A) 0.64
Description : Co-efficient of discharge (Cd ) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv ; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about (A) 0.42 (B) 0.62 (C) 0.82 (D) 0.98
Last Answer : (B) 0.62