Description : The equation, (NSt × N2/3 Pr ) = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None of these
Last Answer : (A) Colburn
Description : The equation, Nst = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None o
Last Answer : (B) Reynolds
Description : According to Chilton-Colburn analogy for mass transfer, NSt .NSc 2/3 is equal to (A) f (B) f/2 (C) 2f (D) 1/f
Last Answer : (B) f/2
Description : Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is ... convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr
Last Answer : (D) The Colburn jH factor for heat transfer is given by Nst Npr
Description : Reynold's analogy states that (A) Nst α f (B) Nst α NRe (C) NNu α f (D) NRe α f
Last Answer : (A) Nst α f
Description : The equation f -0.5 = 4.07 loge (NRe √f) -0.6 is called the __________. (A) Colebrook formula (B) Von-Karman equation (C) Fanning equation (D) None of these
Last Answer : (B) Von-Karman equation
Description : The equation relating friction factor to Reynold number, f -0.5 = 4 loge (NRe /√f) -0.4 , is called the __________ equation. (A) Nikuradse (B) Von-Karman
Last Answer : (B) Ergun's
Description : Colburn analogy is applicable for the value of Prandtl number from (A) 0.001 to 1 (B) 0.6 to 120 (C) 0.5 to 5 (D) 120 to 400
Last Answer : (B) 0.6 to 120
Description : Prandtl and Reynolds analogy are same, when Prandtl number is (A) 0.5 (B) 1 (C) > 2 (D) 1.5
Last Answer : (B) 1
Description : Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations. (A) Sherwood number in mass transfer is analogous to Nusselt number in heat transfer ... heat transfer (D) Reynolds number remains the same in both heat and mass transfer
Last Answer : (C) Reynolds number in mass transfer is analogous to Grashoff number in heat transfer
Description : JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by (A) Nsh = 2 (B) Nst = 2 (C) Nsc = 2 (D) None of these
Last Answer : (A) Nsh = 2
Description : According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor) (A) 2f (B) f (C) f/2 (D) f/4
Last Answer : (C) f/2
Description : Reynold's analogy states that (where, St = Stanton number f = friction factor) (A) St = f/2 (B) St = f/4 (C) St = 4f (D) St = f 1/2
Last Answer : (A) St = f/2
Description : For flow over a flat plate, the ratio of thermal boundary layer thickness, 'xt' and hydrodynamic boundary layer thickness 'x' is equal to (where, NPr = Prandtl number) (A) NPr (B) NPr 1/3 (C) NPr -1 (D) NPr -1/3
Last Answer : (B) NPr 1/3
Description : Nusselt number (for forced convection heat transfer) is a function of the __________ number. (A) Prandtl (B) Reynolds (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : jH factor for heat transfer depends upon the __________ number. (A) Biot (B) Nusselt (C) Reynolds (D) Prandtl
Last Answer : (C) Reynolds
Description : Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff
Last Answer : (D) Prandtl & Grashoff
Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side
Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger
Description : Prandtl and Reynold's analogies are identical for Prandtl number value of (A) 0 (B) 0.5 (C) 1 (D) 5
Last Answer : (C) 1
Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers
Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension
Description : . For what value of Prandtl number, the Col-burn analogy is (A) 0.06 to 120 (B) 0.6 to 120 (C) 1 to 103 (D) 1 to 50
Description : Which of the following is unimportant in forced convection? (A) Reynolds number (B) Prandtl number (C) Grashoff number (D) None of these
Last Answer : (C) Grashoff number
Description : Natural convection is characterised by (A) Grashoff number (B) Peclet number (C) Reynolds number (D) Prandtl number
Last Answer : (A) Grashoff number
Description : Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number
Last Answer : Option D
Description : Which of the following equations is valid for laminar flow of a fluid through packed bed? (A) Fanning equation (B) Kozeny - Karman equation (C) Hagen-Poiseuille equation (D) Blake-Plummer equation
Last Answer : (B) Kozeny - Karman equation
Description : Pick out the wrong statement. (A) The Reynolds analogy for mass transfer is given by Lewis relation and is applicable, when Schmidt number is one (B) Sherwood number for flow in pipes can be expressed ... flux of a component A in binary mixture of A and B is given by - Dab'.dCA/dz
Last Answer : (C) According to film theory for equimolar counter diffusion, the mass transfer coefficient is given by DAB(B)P - 3, Q - 2
Description : The reaction in which the rate equation corresponds to a stoichiometric equation, is called a/an __________ reaction. (A) Elementary (B) Non-elementary (C) Parallel (D) Autokinetic
Last Answer : (A) Elementary
Description : According to Bond crushing law, the work required to form particle of size 'D' from very large feed is (where (S/V)p and (S/V) f are surface to volume ratio of the product and feed respectively). (A) (S/V)p (B) √(S/V)p (C) (S/V) 2 p (D) (S/V) f
Last Answer : (B) √(S/V)
Description : For what value of Prandtl number, St = f/2? (A) 1.5 (B) 1 (C) > 1 (D) < 1
Description : Dittus-Boelter equation cannot be used for molten metals mainly due to its very low (A) Prandtl number (B) Grashoff number (C) Thermal conductivity (D) Viscosity
Last Answer : (A) Prandtl number
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 : NRe . NPr ) (D/L) is called the __________ number (A) Peclet (B) Stanton (C) Graetz (D) None of these
Last Answer : (C) Graetz
Description : NGr × NPr ) is called the __________ number. (A) Graetz (B) Rayleigh (C) Nusselt (D) Stanton
Last Answer : (B) Rayleigh
Description : Consider the steady-state absolute amplitude equation shown below, if ω / ω n = √2 then amplitude ratio (X/Y) =? (X/Y) = √{1 + [ 2ξ (ω/ω n )] 2 } / √{[1 – (ω/ω n ) 2 ] 2 + {2ξ (ω/ω n ) 2 } A. 0 B. 1 C. less than 1 D. greater than 1
Last Answer : B. 1
Description : The value of x and y which satisfy the equations : √ e) x=1,y=0 f) x=0,y=0 g) x=1,y=1 h) x=0,y=1
Last Answer : f) x=0,y=0
Description : What is the meaning of the name Karman ?
Last Answer : The Arabic name Karman means "generous" , " selfless" , " one who respects others".
Description : Border line which separates outer space from Earth’s atmosphere is known as------? A. Durand line B. Space line C. Venus line D. Karman line (Answer)
Last Answer : D. Karman line (Answer)
Description : Singing of telephone wires in the wind occurs due to : (a) Vibrations caused by birds as they sit on or get off, the wires (b) Tensioning at the ends (c) Magnus effect (d) Generation of Karman Vortex street
Last Answer : (d) Generation of Karman Vortex street
Description : Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels. (A) 90 (B) 120 (C) 150 (D) 180
Last Answer : (B) 120
Description : Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per m2 of steel strip. (A) 5-10 (B) 1000-1500 (C) 120-500 (D) 1500-3000
Last Answer : Option C
Description : The Dittus-Boelter equation for convective heat transfer [(i.e. h = 0.023 (K/D) (Re) 0.8 (Pr) 0.4 ] cannot be used for (A) Low Reynold's number (B) Very low Grashoff number (C) Molten metals (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
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 : Which of the fluid forces are not considered in the Reynold's equation of flow? (A) Viscous forces (B) Turbulent forces (C) Pressure forces (D) Compressibility forces
Last Answer : (D) Compressibility forces
Description : Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number? (A) Fanning equation (B) Blake-Plummer equation (C) Hagen-Poiseuille equation (D) Kozeny-Carman equation
Last Answer : (B) Blake-Plummer equation
Description : Stoke's equation is valid in the Reynolds number range (A) 0.01 to 0.1 (B) 0.1 to 2 (C) 2 to 10 (D) 10 to 100
Last Answer : (A) 0.01 to 0.1
Description : Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the __________ number. (A) Schmidt (B) Sherwood (C) Peclet (D) Stanton
Last Answer : (A) Schmidt
Description : The ratio of momentum diffusivity to thermal diffusivity is the __________ number. (A) Prandtl (B) Nusselt (C) Stanton (D) Grashoff
Last Answer : (A) Prandtl
Description : The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt
Last Answer : (B) Prandtl
Description : For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone. (A) Extremely low (B) Low (C) High (D) No
Last Answer : (C) High
Description : Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer. (A) Grashoff (B) Biot (C) Stanton
Last Answer : (A) Grashoff