Description : The Reynolds number for an ideal fluid flow is (A) 4 (B) 2100-4000 (C) 4000 (D) ∞
Last Answer : (D) ∞
Description : Laminar flow of a Newtonian fluid ceases to exist, when the Reynolds number exceeds (A) 4000 (B) 2100 (C) 1500 (D) 3000
Last Answer : (B) 2100
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 : Creeping flow around a sphere is defined, when particle Reynolds number is (A) < 2100 (B) < 0.1 (C) > 2.5 (D) < 500
Last Answer : (B) < 0.1
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
Last Answer : (B) 1
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 : A fluid (µ/ρ) = 0.01 cm2 /sec is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec. (A) 7 (B) 700 (C) 7000 (D) 630
Last Answer : (A) 7
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 : 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 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 : Which of the following denotes the effect of compressibility in fluid flow? (A) Weber number (B) Mach number (C) Euler number (D) Reynolds number
Last Answer : (B) Mach numbe
Description : Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (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 : 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)
Description : Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the ... (A) Increase (B) Decrease (C) Remain unchanged (D) Data insufficient to predict relative pressure drop
Last Answer : (B) Decrease
Description : For the Stoke's law to be valid in the case of a falling sphere in a fluid, the (A) Reynolds number (based on sphere diameter) should be < 1 (B) Flow around the sphere should be in turbulent region (C) Sphere must be metallic (D) Fluid density should be constant
Last Answer : (C) Sphere must be metallic
Description : __________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical. (A) Mach (B) Reynolds (C) Froude (D) Weber
Last Answer : (C) Froude
Description : Reynolds number of a fluid flowing in a circular pipe is 10,000. What will be the Reynolds number when the fluid velocity is decreased by 30% & the pipe diameter is increased by 30%? (A) 9,100 (B) 13,000 (C) 7,000 (D) 2,550
Last Answer : (A) 9,100
Description : Experimental study of laminar fluid flow through a circular tube was conducted by (A) Reynolds (B) Hagen and Poiseuille (C) Pascal (D) Blake-Plummer
Last Answer : (B) Hagen and Poiseuille
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 : 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 : 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
Last Answer : (C) 0
Description : What is the value of Joule-Thomson co-efficient for an ideal gas? (A) +ve (B) -ve (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
Last Answer : (B) 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 : Laminar flow region is said to exist during agitation of a liquid in an agitator, when the value of Reynolds number is (A) > 10 (B) < 10 (C) > 100 (D) < 100
Last Answer : (B) < 10
Description : The value of critical Reynolds number for pipe flow is (A) 1,300 (B) 10,000 (C) 100,000 (D) None of these
Last Answer : (A) 1,300
Description : Reynolds number for flow of water at room temperature through 2 cm dia pipe at an average velocity of 5 cm/sec is around (A) 2000 (B) 10 (C) 100 (D) 1000 Answer:
Last Answer : (D) 1000
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 : At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5 : Power number Re = ρ N D2 ... Re -1.0 (B) Po ∝ Re 0.0 (C) Po ∝ Re 0.5 (D) Po ∝ Re 1.0
Last Answer : (B) Po ∝ Re 0.0 (C) Po ∝ Re 0.5
Description : An ideal voltage amplifier should have A) Ri = 0, R0 = 0 B) Ri = 0, R0 =∞ C) Ri = ∞, R0 = 0 D) Ri = ∞, R0 = ∞.
Last Answer : C) Ri = ∞, R0 = 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 : 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) ∞
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 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 eddy diffusivity for a liquid in plug flow must be (A) 1 (B) 0 (C) ∞ (D) Between 0 and 1
Description : If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid (A) Remains unchanged (B) Increases (C) Increases or decreases depending on number of shell passes (D) Decreases
Last Answer : (D) Decreases
Description : The co-efficient of drag and lift for an incompressible fluid depends on the (A) Reynolds number (B) Froude number (C) Mach number (D) All (A), (B) and (C)
Last Answer : (A) Reynolds numbe
Description : Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K (A) 0 (B) ∞ (C) 50 (D) 100
Last Answer : (B) ∞
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 : Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will (A) Increase (B) Decrease (C) Remain same (D) Data insufficient to predict pressure drop
Last Answer : (A) Increase
Description : Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5
Last Answer : (C) Re0.8, Re0.5
Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10
Last Answer : (A) 3.06 × 10
Description : Stoke's law is valid, when NRe, p is less than (A) 2 (B) 100 (C) 2100 (D) 700
Last Answer : (A) 2
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 : The continuity equation in ideal fluid flow states that (A) Net rate of inflow into any small volume must be zero (B) Energy is not constant along a streamline (C) Energy is constant along a streamline (D) There exists a velocity potential
Last Answer : (A) Net rate of inflow into any small volume must be zero
Description : Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent ... of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid
Last Answer : (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity