Description : The term "laminar flow" is most often associated with the description of: w) conduction of sound by waves x) current flow in transistors y) effects of viscosity of liquids z) passage of light rays through a liquid
Last Answer : ANSWER: Y -- EFFECTS OF VISCOSITY OF LIQUIDS
Description : When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all sides. This type of flow is known as (A) Steady flow (B) Turbulent flow (C) Vortex flow
Last Answer : Answer: Option C
Description : In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow? (A) ... level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe
Last Answer : (B) Water flow in the suction and discharge pipe of a reciprocating pump
Description : The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32
Last Answer : Answer: Option D
Description : Power consumption during turbulent flow in agitation tank is proportional to the __________ of the liquid. (A) Viscosity (B) Thermal conductivity (C) Surface tension (D) Density
Last Answer : (D) Density
Description : Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, ... system (D) In a continuous flow reactor, both the reactants and the products flow out continuously
Last Answer : (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system
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 : 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 : The dynamic viscosity of the liquid __________ with rise in temperature. (A) Remain unaffected (B) Increases (C) Decreases (D) None of these
Description : A thick liquid like syrup has a __________ viscosity than a light liquid like water. (A) Lesser (B) Greater (C) Same (D) None of these
Last Answer : Answer: Option B
Description : Viscous force is the __________ of shear stress due to viscosity and cross-section area of flow. (A) Sum (B) Different (C) Product (D) Ratio
Description : A flow in which __________ force is dominating over the viscosity is called turbulent flow. (A) Elastic (B) Surface tension (C) Viscous (D) Inertia
Description : Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc ) is proportional to __________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance). (A) √μ (B) 1/√μ (C) 1/μ (D) 1/μ
Last Answer : (B) 1/√μ
Description : The effect of friction on the flow of steam through a nozzle is to decrease the __________ of steam. (A) Wetness (B) Mass flow rate (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'
Last Answer : (C) Both 'a' & 'b'
Description : The process of diffusion of one liquid into the other through a semi permeable membrane is called (A) Viscosity (B) Osmosis (C) Surface tension (D) Cohesion
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 : 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 : The flow of water through the hole in the bottom of a wash basin is an example of (A) Steady flow (B) Uniform flow (C) Free vortex (D) Forced vortex
Description : A flow through a long pipe at decreasing rate is called __________ uniform flow. (A) Steady (B) Unsteady (C) Both A and B (D) None of these
Description : According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain. (A) Equal to (B) Directly proportional (C) Inversely proportional (D) None of these
Description : The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow. (A) Steady uniform (B) Steady non uniform (C) Unsteady uniform
Last Answer : (B) Steady non uniform
Description : Which one of the following statements is correct ? a) For water at 100o Celsius at sea level, the vapour pressure is equal to atmospheric pressure b) Surface energy (or tension) is caused by ... it both in static and in dynamic conditions d) Air is 50,000 times more compressible than water
Last Answer : c) Viscosity of a fluid is the property exhibited by it both in static and in dynamic conditions
Description : When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure (A) Varies as the square of the radial distance B) Increases linearly as ... as the square of the radial distance (D) Decreases as the square of the radial distance
Last Answer : Answer: Option A
Description : The time taken for gravity flow of a fixed volume of liquid (as in Redwood viscometer) is directly proportional to its (A) Absolute viscosity (B) Ratio of absolute viscosity to density (C) Density (D) Reynolds number
Last Answer : (B) Ratio of absolute viscosity to density
Description : Which of the following is not applicable to liquid fuels? a) the viscosity of a liquid fuel is a measure of its internal resistance to flow. b) the viscosity of all liquid fuels decreases with ... the viscosity of liquid fuels, higher will be its heating value d) viscous fuels need heat tracing
Last Answer : c) higher the viscosity of liquid fuels, higher will be its heating value
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 : 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 : A/an __________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor. (A) Isolated (B) Closed (C) Open (D) None of these
Last Answer : (C) Open
Description : The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is (A) Directly proportional to (radius)2 (B) Inversely proportional to (radius)2 (C) Directly proportional to (radius)4 (D) Inversely proportional to (radius)
Description : The intensity of pressure at any point, in a liquid, is (A) Directly proportional to the area of the vessel containing liquid (B) Directly proportional to the depth of liquid from the ... length of the vessel containing liquid (D) Inversely proportional to the depth of liquid from the surface
Description : When a cylindrical vessel containing liquid is resolved, the surface of the liquid takes the shape of (A) A triangle (B) A paraboloid (C) An ellipse (D) None of these
Description : An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called (A) Weir (B) Notch (C) Orifice (D) None of these
Description : During agitation of liquids, power consumption during laminar flow is not proportional to the (A) Density of the liquid (B) Viscosity of the liquid (C) Cube of impeller diameters (D) Square of rotational speed
Last Answer : (A) Density of the liquid
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 : Which of the following is the term used for the resistance of a liquid system to flow? w) surface tension x) diffusion y) viscosity
Last Answer : ANSWER: Y -- VISCOSITY
Description : Pick out the wrong statement. (A) For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1 (B) For calculating forces and ... Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
Last Answer : Option B
Description : Explain the effect of increasing the temperature of a liquid, on intermolecular forces operating between its particles. What will happen to the viscosity of a liquid if its temperature is increased? Arrange the following in increasing order of viscosity-water, hexane, glycerine.
Last Answer : Ans. On increasing the temperature , the kinetic energy of liquid molecules increases so that it can overcome the attractive forces between the molecules and hence liquid can flow more easily i.e. viscosity decreases. Order of increasing viscosity : hexane < water < glycerine.
Description : To avoid an interruption in the flow of a siphon, an air vessel is provided (A) At the inlet (B) At the outlet (C) At the summit (D) At any point between inlet and outle
Description : An air vessel is provided at the summit in a siphon to (A) Avoid interruption in the flow (B) Increase discharge (C) Increase velocity (D) Maintain pressure difference
Description : In a/an __________ vessel, the fluid enters and leaves following plug flow. (A) Open (B) Closed (C) Open-closed (D) Close-opened
Last Answer : (B) Closed
Description : What is the effect of temperature on surface tension and viscosity of a liquid?
Last Answer : Ans. Both decrease by increasing temperature.
Description : Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids? (A) Dittus-Boelter equation (B) Sieder-Tate equation (C) Nusselt equation (D) None of these
Last Answer : (B) Sieder-Tate equation
Description : In a forward feed multiple effect evaporator unit (A) Viscosity of liquid is highest in first effect (B) Transfer from effect to effect is done by pumps (C) No pump is required to withdraw the product from the last effect (D) None of these
Last Answer : (D) None of these
Description : State the effect of temperature and adulteration on viscosity of liquid.
Last Answer : Temperature: The viscosity of liquid is inversely proportional to the temperature of the liquid. Adulteration: When adulteration of soluble substance is added to the liquid its viscosity goes on increasing.
Description : The variation in the volume of a liquid with the variation of pressure is called its (A) Surface tension (B) Compressibility (C) Capillarity (D) Viscosity
Description : Choose the wrong statement (A) Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force (B) Viscosity is due primarily to interaction between fluid molecules (C) Viscosity of liquids decreases with increase in temperature (D) Viscosity of liquid
Description : The speed at which a liquid escapes from a vessel through an orifice is given by _________. a. Archimedes Principle b. Evangelista’s Law c. Torricelli’s Theorem d. Bernoulli’s Equation
Last Answer : Torricelli’s Theorem
Description : For high sensivity of the bubble tube (A) A liquid of low viscosity is used (B) A liquid of low surface tension is used (C) The bubble space should be long (D) All the above
Last Answer : (D) All the above
Description : The sensitivity of a bubble tube can be increased by (A) Increasing the diameter of the tube (B) Decreasing the length of bubble (C) Increasing the viscosity of liquid (D) Decreasing the radius of curvature of tube
Last Answer : (A) Increasing the diameter of the tube
Description : 12. Kinematic viscosity is the product of dynamic viscosity and the density of the liquid. A) Yes B) No
Last Answer : B