According to Reynolds analogy, Stanton number is equal to (where, f =
Fanning friction factor)
(A) 2f
(B) f
(C) f/2
(D) f/4
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 : 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 correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow
Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow
Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number
Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads
Description : Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : What is the value of Fanning friction factor f ' for smooth pipe at NRe = 10 6 approximately? (A) 0.003 (B) 0.01 (C) 0.1 (D) 0.3
Last Answer : (A) 0.003
Description : Fanning friction factor is equal to (where, fB = Blasius friction factor). (A) fB /4 (B) fB /2 (C) 4fB (D) 2fB
Last Answer : (A) fB /4
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 : Which of the following is not a dimension-less parameter? (A) Euler number (B) Specific gravity (C) Fanning friction factor (D) None of these
Last Answer : (D) None of these
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, Nst = (f/2)/[1 + 5 (Npr - 1) √(f/2)], corresponds to __________ analogy. (A) Von-Karman (B) Reynolds (C) Colburn (D) Prandtl
Last Answer : (D) Prandtl
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 : Reduction in vibration amplitude after one complete cycle of single degree free vibration with dry friction damping is_____, if where F"= frictional force between mass and surface and k =stiffness of the system. a)4F/k a b) 2f/K C) 3F/k D)8F/k
Last Answer : a)4F/k
Description : Pressure drop in a packed bed for laminar flow is given by the __________ equation. (A) Kozeny-Carman (B) Blake-Plummer (C) Leva's (D) Fanning friction factor
Last Answer : (A) Kozeny-Carman
Description : Which of the following is dimensionless? (A) Angular velocity (B) Fanning friction factor (C) Specific volume (D) None of these
Last Answer : (B) Fanning friction factor
Description : Fanning friction factor equation applies to the __________ fluid flow. (A) Non-isothermal condition of (B) Compressible (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (D) Neither (A) nor (B)
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 : The friction factor for turbulent flow in a hydraulically smooth pipe (A) Depends only on Reynolds number (B) Does not depend on Reynolds number (C) Depends on the roughness (D) None of these
Last Answer : (A) Depends only on Reynolds number
Description : The friction factor is (A) Always inversely proportional to the Reynolds number (B) Not dimensionless (C) Not dependent on the roughness of the pipe (D) None of these
Description : In turbulent flow, a rough pipe has the same friction factor as a smooth pipe (A) In the zone of complete turbulence (B) When the roughness projections are much smaller than the thickness of ... ) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number
Last Answer : (B) When the roughness projections are much smaller than the thickness of the laminar film
Description : Which of the following quantities are computed by using the hydraulic radius for non-circular ducts? (A) Velocity and relative roughness (B) Head loss and velocity (C) Reynold number, relative roughness and head loss (D) Reynolds number and friction factor
Last Answer : (C) Reynold number, relative roughness and head loss
Description : A pipe is defined as 'hydraulically smooth', if the friction factor (A) Is not a function of Reynolds number (B) For a given Reynolds number remains constant even on further smoothening of the pipe (C) Is zero irrespective of the Reynolds number (D) None of these
Last Answer : (B) For a given Reynolds number remains constant even on further smoothening of the pipe
Description : For a given Reynolds number, in a hydraulically smooth pipe, further smoothening __________ the friction factor. (A) Brings about no further reduction of (B) Increases (C) Decreases (D) None of these
Last Answer : (A) Brings about no further reduction of
Description : All analogy equations connecting friction factor and heat transfer coefficient apply only to (A) Wall or skin friction (B) Form friction (C) Both (A) and (B) (D) Turbulent flow
Last Answer : (A) Wall or skin friction
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 : 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 : In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said ... co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)
Last Answer : (C) Friction co-efficient for flows at equal Reynold number
Description : A concave mirror produces a real, inverted image of the same size of the object. Then, the object is at a distance (a) Less than f from the mirror (b) Equal to f from the mirror (c) Equal to 2f from the mirror (d) Larger than 2F from the mirror where f is the focal length of the mirror
Last Answer : Ans:(c)
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
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 : 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 : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Description : Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed: (i) at the centre of curvature of a concave mirror (ii) between the pole P and focus F of ... front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics
Last Answer : Answer. Nature of image: Real, inverted and same size image is formed at the centre of curvature. Nature of image: Virtual, enlarged and erect image is formed behind the mirror. Nature of image: Virtual ... : Virtual, erect and diminished image is formed between O and F on the same side of object.
Description : If `f(x) = x^(2) - 5x -36` and `g(x) = x^(2) + 9x + 20,` then for what values of `x` is `2f(x) = 3g(x)` ?
Last Answer : If `f(x) = x^(2) - 5x -36` and `g(x) = x^(2) + 9x + 20,` then for what values of `x` is `2f(x) = 3g(x)` ?
Description : Two bodies kept at a certain distance feel a gravitational force F to each other. If the distance between them is made double the former distance, the force will be - (1) 2F (2) F/2 (3) 4F (4) F/4
Last Answer : (4) F/4
Description : In coulomb damping, the amplitude of motion in each cycle is reduced by A. F/K B. 2F/K C. 4F/K D. F/4K
Last Answer : C. 4F/K
Description : An object is placed beyond 2F, in front of a convex lens, image will be formed : (a) between F and 2F (b) at focus (c) at the centre of curvature (d) between focus and Optical centre
Last Answer : (a) between F and 2F
Description : A concave lens can form a real and inverted image, when : (a) Object is placed at 2f (b) Object is placed beyond 2f (c) Object is placed between f and 2f (d) It can never form a real and
Last Answer : (d) It can never form a real and inverted image.
Description : If d is the diameter of the pipe, p is the total internal pressure, f is the permissible tensile stress and n is the effective of the joint, the thickness t of metal pipe, is (A) n (pd/2f) (B) (1/n) (pd/2f) (C) (1/n) (pd/3f) (D) (1/n) (pf/d
Last Answer : (B) (1/n) (pd/2f)
Description : The maximum magnitude of shear stress due to shear force F on a rectangular section of area A at the neutral axis, is (A) F/A (B) F/2A (C) 3F/2A (D) 2F/3A
Last Answer : (C) 3F/2A
Description : When object is placed _______ in front of convex lens than image formed is virtual, erect, magnified and on same side beyond F . a) between optical centre and F b)At F c)between F and 2F d)2F
Last Answer : a) between optical centre and F
Description : In case of convex lens when the image formed is real, inverted and same size as the object then the object should have been at ______ position of lens. a) infinity b)focus c)2F d)between F and 2F
Last Answer : c)2F
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 : The viscous friction co-efficient, in force-voltage analogy, is analogous to?
Last Answer : The viscous friction co-efficient, in force-voltage analogy, is analogous to resistance.
Description : According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe) (A) flv²/2gd (B) flv²/gd (C) 3flv²/2gd (D) 4flv²/2gd
Last Answer : Answer: Option D
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 : jH factor for heat transfer is not a function of the __________ number. (A) Reynolds (B) Nusselt (C) Grashoff (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : jH factor for heat transfer depends upon the __________ number. (A) Biot (B) Nusselt (C) Reynolds (D) Prandtl
Last Answer : (C) Reynolds
Description : Froude number is not a factor (A) For Reynolds number greater than 300 (B) When there is no vortex formation (C) For unbaffled tank (D) None of these
Last Answer : (B) When there is no vortex formation