Description : For an ideal plug flow reactor, the value of Peclet number is (A) 0 (B) 1 (C) 10 (D) ∞
Last Answer : (A) 0
Description : What is the dispersion number for a plug flow reactor? (A) 0 (B) ∞ (C) 1 (D) -1
Description : The vessel dispersion number (D/μL) for plug flow is (A) 0 (B) 500 (C) 750 (D) ∞
Description : The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________ (A) 1 (B) 0.5 (C) 10 (D) 0
Last Answer : (A) 1
Description : Pick out the wrong statement. (A) The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same for NSc = NPr= 1 (B) 1 Nm3 of dry air is lighter ... ) The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass diffusivity
Last Answer : (B) 1 Nm3 of dry air is lighter than 1Nm3 of humid air
Description : In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always (A) < 1 (B) > 1 (C) 1 (D) ∞
Last Answer : (A) < 1
Description : Liquid diffusivity is of the order of __________ cm2 /second. (A) 0.01 (B) 0.1 (C) 10 -5 to 10 -6 (D) > 1
Last Answer : (C) 10 -5 to 10
Description : At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes (A) 1 (B) 0 (C) ∞ (D) None of these
Last Answer : (C) ∞
Description : For an ideal fluid flow, Reynolds number is (A) 2100 (B) 100 (C) 0 (D) ∞
Last Answer : (D) ∞
Description : Colebrook equation for friction factor in turbulent flow is given by, f -0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to (A) 0 (B) 1 (C) ∞ (D) 0.5
Last Answer : (B) 1
Description : The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is: (A) ∞ (B) 0 (C) 1 (D) > 1
Last Answer : (C) 1
Description : The exit age distribution of a fluid leaving a vessel (denoted by E) is used to study the extent of non-ideal flow in the vessel. The value of ∫∞ 0 E.dt is (A) 0 (B) 1 (C) ∞ (D) √2π
Description : A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor volume, it should be operated such that the temperature along the length (A) ... Increases (C) Is at the highest allowable temperature throughout (D) First increases and then decreases
Last Answer : (C) Is at the highest allowable temperature throughout
Description : In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a ... preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the (A) Temperature and pressure (B) Concentration (C) Nature of the constituents (D) None of these
Last Answer : (D) None of these
Description : Molecular diffusivity of a liquid (A) Increases with temperature (B) Decreases with temperature (C) May increase or decrease with temperature (D) Is independent of temperature
Last Answer : (A) Increases with temperature
Description : With increase in temperature, the leaching rate increases because of the (A) Increased diffusivity (B) Decreased viscosity of liquid (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which ‘D’ is the diffusivity of solute, is (A) D/a (B) D/2a (C) Proportional to √D (D) Dependent on the Reynolds number
Last Answer : (D) Dependent on the Reynolds number
Description : With increase in temperature, the leaching rate increases due to (A) Decreased liquid viscosity (B) Increased diffusivity (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary
Last Answer : (B) Molecular diffusion in solid is much faster than that in liquids
Description : In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (θ) and thermal diffusivity (α). The units of these quantities are. (A) μ , α and θ all have units of m/ ... μ has unit of m/s (D) α and θ have units of m/s, while μ has unit of m2/s
Last Answer : Option C
Description : In gas-liquid contact operation, the number of ideal stages, N = (xa - xb )/(xb - x *b ). This is true when the stripping factor 'S' is (A) S > 1 (B) S < 1 (C) S = 1 (D) S = ∞
Last Answer : (A) S > 1
Description : The driving point impedance with poles at ω = 0(zero) and ω = ∞ (infinity) must have the (a) s term in the denominator and an excess term in the numerator (b) s term in the ... the numerator and denominator (d) s term in the denominator and equal number of terms in the numerator and denominator
Last Answer : The driving point impedance with poles at ω = 0(zero) and ω = ∞ (infinity) must have the s term in the denominator and an excess term in the numerator
Description : The Reynolds number for an ideal fluid flow is (A) 4 (B) 2100-4000 (C) 4000 (D) ∞
Description : In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. (A) 20 (B) 60 (C) 120 (D) ∞
Description : . Pick out the wrong statement. (A) The eddy viscosity is a function of the type of turbulence involved (B) The eddy viscosity is a fluid property (C) The viscosity of gas increases with increase in temperature (D) The viscosity of a liquid increases with decrease in temperature
Last Answer : (B) The eddy viscosity is a fluid property
Description : The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit ... /kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000
Last Answer : (C) 600
Description : Reversing the current flow through a coil will ___________. A. reduce the amount of flux produced B. have no effect on the eddy currents produced C. reduce the power consumed D. reverse its two-pole field
Last Answer : Answer: D
Description : Currents that flow in circles inside a disc are known as A. eddy currents B. circular currents C. air currents D. alternating curent
Last Answer : eddy currents
Description : The diffusivity (D) in a binary gas mixture is related to the temperature (T) as (A) D ∝ T (B) D ∝ T 0.5 (C) D ∝ T 1.5 (D) D ∝ T
Last Answer : (C) D ∝ T 1.5
Description : If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is (A) 0 (B) 1 (C) < 1 (D) > 1
Description : For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the ... the catalyst diffusivity is reduced (D) Catalyst size is increased or the catalyst diffusivity is increased
Last Answer : (B) Catalyst size is reduced or the catalyst diffusivity is increased
Description : Cetane number of alpha methyl naphthalene is assumed to be (A) 0 (B) 100 (C) 50 (D) ∞
Description : Octane number of n-heptane is assumed to be (A) 100 (B) 0 (C) 70 (D) ∞
Last Answer : (B) 0
Description : What is the selectivity index, if the grade of tailings & concentrate is the same? (A) 0 (B) ∞ (C) 1 (D) 0.5
Description : Compressibility co-efficient for an absolutely compressible cake is (A) 0 (B) 1 (C) 0 to 1 (D) ∞
Description : At what value of reflux ratio, number of theoretical plates in a distillation column is minimum? (A) 0 (B) 1 (C) ∞ (D) < 1
Description : The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases 'A' and 'B' is (A) 1 (B) ∞ (C) 0.5
Last Answer : (B) ∞
Description : The value of NA/(NA + NB) for steady state molecular diffusion of gas 'A' through non-diffusing gas 'B' is (A) 1 (B) ∞ (C) 0.5 (D) 2
Description : The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is (A) 0 (B) ∞ (C) -ve (D) +ve
Last Answer : (C) -ve
Description : The relative volatility of a binary mixture at the Azeotropic composition is (A) 1 (B) > 1 (C) 0 (D) ∞
Description : In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 ... temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature
Description : What is the thermal conductivity of a perfect heat insulator? (A) Zero (B) One (C) ∞ (D) Between 0 and ∞
Last Answer : (A) Zero
Description : Absorptivity and reflectivity of a perfect black body are respectively (A) 1 and 0 (B) 0 and 1 (C) 1 and ∞ (D) 0 and 0.5
Last Answer : (A) 1 and 0
Description : For an incompressible fluid, the bulk modulus of elasticity is (A) 5 kg/m3 (B) ∞ N/m2 (C) 1 N (D) 0 N/m
Last Answer : (B) ∞ N/m2
Description : If Thiele modulus is __________, then the pore diffusion resistance in a catalyst may be considered as negligible. (A) 0 (B) ∞ (C) < 0.5 (D) > 0.5
Last Answer : (C) < 0.5
Description : What is the dispersion number for a CSTR? (A) 0 (B) 1 (C) < 1 (D) ∞
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
Last Answer : (C) 0
Description : The difference between isothermal compressibility and adiabatic compressibility for an ideal gas is (A) 0 (B) +ve (C) -ve (D) ∞
Last Answer : (B) +ve
Description : 4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is (A) 4 J (B) ∞ (C) 0 (D) 8 J