Description : In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is (A) The velocity of sound (B) Dependent on its cross-sectional area (C) Dependent on fluid viscosity (D) Dependent on fluid density
Last Answer : (A) The velocity of sound
Description : The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonian fluid in a circular pipe is (A) 0.5 (B) 1 (C) 2 (D) 0.66
Last Answer : (A) 0.5
Description : Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian ... at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows
Last Answer : (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5
Description : Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b
Last Answer : (B) Mean velocity
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 : In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity) (A) Vavg (B) 1.2 Vavg (C) 1.5 Vavg (D) 1.8 Vavg
Last Answer : (B) 1.2 Vavg
Description : For turbulent flow of Newtonian fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is (A) 0.5 (B) 1 (C) 0.66 (D) < 0.5
Last Answer : (B) 1
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 : What is the maximum recommend pipe velocity for dry and wet gases?
Last Answer : For dry gases, you should design for a velocity of about 100 ft/s while wet gases should be limited to about 60 ft/s.
Description : Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 ... under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum
Last Answer : (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1
Description : Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if ... unstable or has the tendency to react with other components associated with it, at the boiling temperature
Last Answer : (A) Azeotropic mixture is to be separated and the final product is miscible with water
Description : Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both ... steam on shell side (D) Shell and tube heat exchanger with air on shell side and steam inside tubes
Last Answer : (B) Finned tube heat exchanger with air outside and steam inside
Description : At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be (A) Minimum (B) Maximum (C) Zero (D) Could be any value
Last Answer : Answer: Option D
Description : When a liquid is flowing through a pipe, the velocity of the liquid is (A) Maximum at the centre and minimum near the walls (B) Minimum at the centre and maximum near the walls (C) Zero at the centre and maximum near the walls (D) Maximum at the centre and zero near the walls
Last Answer : Answer: Option A
Description : Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the ... 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only
Last Answer : (b) 1 & 3 only
Description : Air is best heated with steam in a heat exchanger of (A) Plate type (B) Double pipe type with fin on steam side (C) Double pipe type with fin on air side (D) Shell and tube type
Last Answer : (C) Double pipe type with fin on air side
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 : Trap is used to remove __________ from steam pipe lines. (A) Steam (B) Condensate (C) Non-condensable (D) None of these
Last Answer : (B) Condensate
Description : In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation ... Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate
Last Answer : (C) Remain unchanged
Description : Loss of heat from untagged steam pipe to the ambient air is by (A) Conduction (B) Convection (C) Radiation (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam
Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature
Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C
Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C
Description : A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just ... to which insulating material is to be put inside (i.e., just next to the pipe)
Last Answer : (A) The better insulation material should be put just next to pipe (i.e., inside)
Description : Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans? (A) Emissivity of pipe surface (B) Diameter & length of the pipe (C) Temperature of hot pipe surface & that of air in the room (D) None of thes
Last Answer : Option D
Description : The diameter of a domestic sewer pipe laid at gradient 1 in 100 is recommended (A) 100 mm (B) 150 mm (C) 200 mm (D) 175 mm
Last Answer : (B) 150 mm
Description : A 300mm diameter pipe, 5mm wall thickness is to be radiographed using the double wall single image technique. The source to be used is Iridium. Which of the following statements is true? a) ... problem with the technique d) Only the double wall, double image technique should be used with Iridium
Last Answer : c) There is no problem with the technique
Description : Over voltage protection is recommended for (a) hydro-electric generators (b) steam turbine generators (c) gas turbine generators (d) all of the above (e) none of the above
Last Answer : (d) all of the above
Description : Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of ... debris C. periodic testing of insulation resistance with a megger D. all of the above
Last Answer : Answer: D
Description : ____________is used to release condensate in pipe work a) steam trap b) valves c) power generators d) none of above
Last Answer : b) valves
Description : Wet steam at 1 MPa flowing through a pipe is throttled to a pressure of 0.1 MPa. If the throttling temperature is110°C, What is the quality of the steam in the pipe? a) 96% b) 86% c) 76% d) 66%
Last Answer : 96%
Description : A steam calorimeter receives steam from a pipe at 0.1 MPa and 20°SH. For a pipe steam pressure of 2 MPa, what is the quality of the steam? a) 95.56% b) 70.10% c) 95.20% d) 85.10% Formula: h1 = hf1 + x1hfg1
Last Answer : 265.4°C, 430.7kJ/kg, 71.4kJ/kg, 1.0327kJ/(kg)(K),502.1 kJ/kg
Description : Calculate the rate of heat transfer by radiation from an unlagged steam pipe, 50 mm o.d. at 393K to air at 293K emissivity e = 0.9.
Last Answer : Rate of heat transfer by radiation Assume length of pipe = 1 m
Description : Pressure gradient in the pipe flow is influenced by the (A) Diameter of pipe (B) Velocity of the fluid (C) Density & viscosity of the fluid (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : In case of laminar flow of fluid through a circular pipe, the (A) Shear stress over the cross-section is proportional to the distance from the surface of the pipe (B) Surface of velocity distribution is a ... occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)
Last Answer : (B) Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder
Description : The head loss in turbulent flow in a pipe varies (A) Directly as the velocity (B) Inversely as the square of the velocity (C) Approximately as the square of the velocity (D) Inversely as the square of the diameter
Last Answer : (C) Approximately as the square of the velocity
Description : Hydraulic intensifier is used for increasing the (A) Rate of velocity of liquid supply (B) Rate of flow through delivery pipeline of a pump (C) Intensity of pressure of the liquid (D) Momentum rate through delivery pipe
Last Answer : (C) Intensity of pressure of the liquid
Description : What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition? (A) 0.5 (B) 0.67 (C) 1 (D) 2
Last Answer : (D) 2
Description : For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a __________ relationship. (A) Logarithmic (B) Linear (C) Hyperbolic (D) Parabolic
Last Answer : (A) Logarithmic
Description : Which of the following factors does not contribute to the pressure drop in a pipeline? (A) Velocity of fluid (B) Size of pipe (C) Length of pipe and number of bends (D) None of these
Last Answer : (D) None of these
Description : he pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe ... then the pressure drop in this case will be (A) Δp (B) 2Δp (C) Δp 2 (D) Δp/2
Last Answer : (B) 2Δp
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 : Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the (A) Pipe length (B) Fluid velocity in the pipe (C) Time taken to close the valve (D) All (A), (B) and (C)
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 : A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is (A) 20 m/sec (B) 10 m/sec (C) 5 √2 m/sec (D) 5 m/sec
Last Answer : (B) 10 m/sec
Description : The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is (A) Parabolic (B) Flat (C) Flat near the wall and parabolic in the middle (D) Parabolic near the wall and flat in the middle
Last Answer : (D) Parabolic near the wall and flat in the middle
Description : The Prandtl Pitot tube measures the (A) Velocity at a point in the flow (B) Pressure at a point (C) Average flow velocity (D) Pressure difference in pipe flow
Last Answer : (A) Velocity at a point in the flow
Description : The head loss in turbulent flow in a pipe varies (A) As velocity (B) As (velocity) 2 (C) Inversely as the square of diameter
Last Answer : (B) As (velocity)
Last Answer : (C) Inversely as the square of diameter
Description : The flow of gas along a pipe in the direction of decreasing pressure causes decrease in its (A) Viscosity (B) Specific volume (C) Velocity (D) None of these
Last Answer : (B) Specific volume
Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ
Last Answer : (B) 1/μ