This set of Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Fluid Properties – 1”.
- Which one of the following is the unit of mass density?
a) kg = m3
b) kg = m2
c) kg = m
d) kg = m - The specific gravity of a liquid has
a) the same unit as that of mass density
b) the same unit as that of weight density
c) the same unit as that of specific volume
d) no unit - The specific volume of a liquid is the reciprocal of
a) weight density
b) mass density
c) specific weight
d) specific volume - Which one of the following is the unit of specific weight?
a) N = m3
b) N = m2
c) N = m
d) N = ms - Which one of the following is the dimension of mass density?
a) [M1 L-3 T0].
b) [M1 L3 T0].
c) [M0 L-3 T0].
d) [M0 L3 T0].
. - Which one of the following is the dimension of specific gravity of a liquid?
a) [M1 L-3 T0].
b) [M1 L0 T0].
c) [M0 L-3 T0].
d) [M0 L0 T0].
. - Which one of the following is the dimension of specific volume of a liquid?
a) [M1 L-3 T0].
b) [M-1 L3 T0].
c) [M-1 L-3 T0].
d) [M0 L3 T0].
. - Which one of the following is the dimension of specific weight of a liquid?
a) [ML-3 T -2].
b) [ML3 T-2].
c) [ML-2 T-2].
d) [ML2 T-2].
. - Two fluids 1 and 2 have mass densities of p1 and p2 respectively. If p1 > p2, which one of the following expressions will represent the relation between their specific volumes v1 and v2?
a) v1 > v2
b) v1 < v2
c) v1 = v2
d) Cannot be determined due to insufficient information.
. - A beaker is filled with a liquid up to the mark of one litre and weighed. The weight of the liquid is found to be 6.5 N. The specific weight of the liquid will be
a) 6:5 kN = m3
b) 6:6 kN = m3
c) 6:7 kN = m3
d) 6:8 kN = m3
. - A beaker is filled with a liquid up to the mark of one litre and weighed. The weight of the liquid is found to be 6.5 N. The specific gravity of the liquid will be
a) 0.65
b) 0.66
c) 0.67
d) 0.68
. - A beaker is filled with a liquid up to the mark of one litre and weighed. The weight of the liquid is found to be 6.5 N. The specific volume of the liquid will be
a) 1 l =kg
b) 1:5 l =kg
c) 2 l =kg
d) 2:5 l =kg
This set of Fluid Mechanics Interview Questions and Answers focuses on “Fluid Properties – 2”.
- Calculate the specific weight and weight of 20dm3 of petrol of specific gravity 0.6.
a) 5886,117.2
b) 5886,234.2
c) 11772,117.2
d) None of the mentioned
. - If 200m3 of fluid has a weight of 1060N measured on the planet having acceleration due to gravity 6.625m/s2, what will be it’s specific volume?
a) 0.8
b) 0.7
c) 0.9
d) 0.5
. - For an incompressible fluid does density vary with temperature and pressure?
a) It varies for all temperature and pressure range
b) It remains constant
c) It varies only for lower values of temperature and pressure
d) It varies only for higher values of temperature and pressure
. - Specific gravity is what kind of property?
a) Intensive
b) Extensive
c) None of the mentioned
d) It depends on external conditions
. - If there is bucket full of oil and bucket full of water and you are asked to lift them, which one of the two will require more effort given that volume of buckets remains same?
a) Oil bucket
b) Water bucket
c) Equal effort will be required to lift both of them
d) None of the mentioned
. - If the fluid has specific weight of 10N/m3 for a volume of 100dm3 on a planet which is having acceleration due to gravity 20m/s2 , what will be its specific weight on a planet having acceleration due to gravity 4m/s2?
a) 5 N/m3
b) 50 N/m3
c) 2 N/m3
d) 10 N/m3
. - Should Specific Wieght of incompressible fluid only be taken at STP?
a) Yes, as specific weight may show large variation with temperature and pressure
b) No, it can be taken for any temperature and pressure
c) It should be taken at standard temperature but pressure may be any value
d) It should be taken at standard pressure but temperature may be any value
. - An instrument with air as fluid was involved in some experiment( specific volume was the characteristic property utilized) which was conducted during day in desert. Due to some reason experiment couldn’t be conducted during day and had to be conducted during night. However there were considerable errors in obtained values. What might be the reason of these errors?
a) It was human error
b) It was instrumental error
c) Error was due to the fact that experiment was conducted at night
d) None of the mentioned
. - A stone weighed 177 N on earth. It was dropped in to oil of specific gravity 0.8 on a planet whose acceleration due to gravity is 5m/s2. It displaced oil having weight of 100N. What was the volume of oil displaced by the stone?
a) 25 Litres
b) 15 Litres
c) 25 m3
d) None of the mentioned
. - An compressible fluid’s specific gravity was measured on earth, on a planet having acceleration due to gravity 5.5 times that of earth, and in space at STP. Where will it be having highest value?
a) on the earth
b) on the planet
c) in the space
d) it will be constant everywhere
his set of Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Viscosity – 1”.
- Water flows between two plates of which the upper one is stationary and the lower one is moving with a velocity V. What will be the velocity of the fluid in contact with the upper plate?
a) V
b) N ⁄ 2
c) 2V
d) 0
. - The viscous force the relative motion between the adjacent layers of a fluid in motion.
Which one of the flowing fits best in the sentence?
a) opposes
b) never affects
c) facilitates
d) may effect under certain conditions
. - The viscosity of a fluid in motion is 1 Poise. What will be it’s viscosity (in Poise) when the fluid is at rest?
a) 0
b) 0.5
c) 1
d) 2
. - Which of the following correctly states how the viscosities of a liquid and a gas will change with temperature?
a) Viscosity increases with the increase in temperature of a liquid and decreases with the increase in temperature of a gas
b) Viscosity increases with the increase in temperature of a liquid and increases with the increase in temperature of a gas
c) Viscosity decreases with the increase in temperature of a liquid and decreases with the increase in temperature of a gas
d) Viscosity decreases with the increase in temperature of a liquid and increases with the increase in temperature of a gas
. - Which one of the following is not a unit of dynamic viscosity?
a) Pa-s
b) N-s/m2
c) Poise
d) Stokes
. - Which of the following is a unit of dynamic viscosity?
a) [M1 L1 T-1].
b) [M1 L-1 T-1].
c) [M1 L-2 T-2].
d) [M1 L-2 T-2].
. - Which one of the following is the CGS unit of dynamic viscosity?
a) Stokes
b) Pa-s
c) m2/s
d) Poise
. - The dynamic viscosity of a fluid is 1 Poise. What should one multiply to it to get the answer in N-s/m2?
a) 0.1
b) 1
c) 10
d) 100
. - Which of the following is a unit of kinematic viscosity?
a) Stokes
b) Pa-s
c) m2=s
d) Poise
. - Which of the following is the dimension of kinematic viscosity?
a) [L1 T-1].
b) [L1 T-2].
c) [L2 T-1].
d) [L2 T-2].
. - The kinematic viscosity of a fluid is 0.1 Stokes. What will be the value is m2/s?
a) 10-2
b) 10-3
c) 10-4
d) 10-5
. - The shear stress at a point in a liquid is found to be 0.03 N/m2. The velocity gradient at the point is 0.15 s-1. What will be it’s viscosity (in Poise)?
a) 20
b) 2
c) 0.2
d) 0.5 - Two horizontal plates placed 250mm have an oil of viscosity 20 poises. Calculate the shear stress in oil if upper plate is moved with velocity of 1250mm/s.
a) 20 N/m2
b) 2 N/m2
c) 10 N/m2
d) None of the mentioned
. - The kinematic viscosity of oil of specific gravity .8 is .0005 .This oil is used for lubrication of shaft of diameter .4 m and rotates at 190 rpm. Calculate the power lost in the bearing for a sleeve length of 90mm. The thickness of the oil film is 1.5mm.
a) 477.65 Watts
b) 955.31 Watts
c) 238.83 Watts
d) None of the mentioned
. - Find the kinematic viscosity of oil having density 1962 g/m3. the force experienced for area of 20 m2 is 4.904 kN and velocity of gradient at that point is 0.2/s.
a) 0.625
b) 1.25
c) 2.5
d) None of the mentioned
. - The velocity distribution for fluid flow over a flat plate is given by u=2y-6y2 in which u is the velocity in metre per second at a distance of y metre above the plate. Determine the shear stress at y=0.15m.Take dynamic viscosity of fluid as 8.6 poise.
a) 0.172 N/m2
b) 0.344 N/m2
c) 0.086 N/m2
d) None of the mentioned
. - In which types of fluids it is observed that momentum transfer dominates cohesive forces with increase in temperature and hence viscosity increases
a) Gases
b) Liquids
c) Solids
d) None of the mentioned
. - What is the characteristic variation shown by the thixotropic fluids in their shear stress vs. rate of shear strain graph?
a) shear stress increases with increase in rate of shear strain
b) shear stress decreases with increase in rate of shear strain
c) shear stress shows variation only after a definite shear stress is reached
d) shear stress has decreasing constant and then variation relationship with rate of shear strain
. - What happens to viscosity in the case of incompressible fluids as temperature is increased?
a) It remains constant
b) It increases
c) It decreases
d) None of the mentioned
. - If a fluid, which has a constant specific gravity, is taken to a planet where acceleration due to gravity is 3 times compared to its value on earth, what will happen to its kinematic viscosity.
a) It increases
b) It decreases
c) It remains constant
d) None of the above
. - In liquids in order to measure the viscosity of fluid experimentally we consider the variation of shear stress with respect to what property?
a) strain
b) shear strain
c) rate of shear strain
d) none of the mentioned
. - For a compressible fluid the kinematic viscosity is affected by temperature and pressure variation.
a) True
b) False - A Hydraulic press has a ram of 30 cm diameter and a plunger of of 2 cm diameter. It is used for lifting a weight of 35 kN. Find the force required at the plunger.
a) 233.3 kN
b) 311.1 kN
c) 466.6 kN
d) 155.5 kN
. - The pressure at a point in the fluid is 4.9 N/cm2. Find height when the fluid under consideration is in oil of specific gravity of 0.85.
a) 5.83 m
b) 11.66 m
c) 17.49 m
d) 8.74 m
. - An open tank contains water upto a depth of 350 cm and above it an oil of specific gravity 0.65 for a depth of 2.5 m. Find the pressure intensity at the extreme bottom of the tank.
a) 5.027 N/cm2
b) 10.05 N/cm2
c) 2.51 N/cm2
d) None of the mentioned
. - The diameters of a small piston and a large piston of a hydraulic jack are 45 mm and 100 mm respectively.Force of 0.09 kN applied on smaller in size piston. Find load lifted by piston if smaller in size piston is 40 cm above the large piston. The density of fluid is 850 kg/m3
a) 60 N/cm2
b) 12 N/cm2
c) 30 N/cm2
d) None of the mentioned
. - If fluid is at rest in a container of a narrow mouth at a certain column height and same fluid is at rest at same column height in a container having broad mouth, will the pressure be different at certain depth from fluid surface.
a) Pressure will be same for both.
b) Pressure will be more for narrower mouth
c) Pressure will be less for narrower mouth
d) None of the mentioned
. - We can draw Mohr’s circle for a fluid at rest.
a) True
b) false
. - Pressure intensity or force due to pressure gradient for fluid at rest is considered as which kind of force?
a) Surface force
b) Body force
c) Force due to motion
d) None of the mentioned
. - Calculate the hydrostatic pressure for water moving with constant velocity at a depth of 5 m from the surface.
a) 49 kN/m2
b) 98 kN/m2
c) since fluid is in motion, we cannot analyse
d) None of the mentioned
. - Pressure distribution for fluid at rest takes into consideration pressure due to viscous force.
a) True
b) False
. - Barometer uses the principle of fluid at rest or pressure gradient for its pressure calculation.
a) True
b) False - What is the pressure in Pascals at a depth of 1m below the water surface?
a) 98100 Pa
b) 980 Pa
c) 98 Pa
d) 1 Pa
. - 15 bar equals to __ Pascals.
a) 105Pa
b) 1.5 x 106 Pa
c) 100 Pa
d) 1000 Pa
. - The pressure at any given point of a non-moving fluid is called the __
a) Gauge Pressure
b) Atmospheric Pressure
c) Differential Pressure
d) Hydrostatic Pressure
. - The device used to measure the fluid pressure is _
a) Hygrometer
b) Calorimeter
c) Manometer
d) Thermometer
. - What type of liquids are measured using a manometer?
a) Heavy liquids
b) Medium Liquids
c) Light Liquids
d) Heavy and light liquids
. - Which among these devices are the best suited for the measurement of high pressure liquids with high accuracy?
a) Dead Weight Gauge
b) Vacuum Gauge
c) Manganin wire pressure
d) Ionization Gauge
. - How do we measure the flow rate of liquid?
a) Coriolis method
b) Dead weight method
c) Conveyor method
d) Ionization method
. - What is the instrument used for the automatic control scheme during the fluid flow?
a) Rotameters
b) Pulley plates
c) Rotary Piston
d) Pilot Static Tube
. - Define Viscosity?
a) Resistance to flow of an object
b) Resistance to flow of air
c) Resistance to flow of fluid
d) Resistance to flow of heat
A. - What is the viscosity of water at 30oC?
a) 80.1
b) 0 .801
c) 801
d) 0.081 - The right limb of a simple U-tube manometer containing mercury is open to the atmosphere while the lift limb is connected to a pipe in which a fluid of specific gravity 0.85 is flowing. The centre of the pipe is 14 cm below the level of mercury in the right limb.Evaluate the pressure of fluid flowing in the pipe if the difference of mercury level in the two limbs is 22 cm.
a) 2.86 N/cm2
b) 5.73 N/cm2
c) 1.43 N/cm2
d) None of the mentioned
. - A single coloumn manometer is connected to a pipe containing a liquid of specific gravity 0.75. Find the pressure in the pipe if the area of reservoir is 250 times the area of tube for the manometer reading. The difference in mercury level is 40 cm. On the left limb the fluid is upto the height of 20 cm.
a) 10.42 N/cm2
b) 5.21 N/cm2
c) 2.60 N/cm2
d) None of the mentioned
. - A Differential manometer is connected at the points A and Bat the centre of two pipes. The pipe A(left limb) contains a liquid of specific gravity = 1.5 while pipe B (right limb)contains a liquid of specific gravity 0.85. The pressure at A and B are .5 kgf/cm2 and 1.2 kgf/cm2 respectively. Find the difference in level of mercuru in the differential manometer. A is 2.5m above B and 5 m above the mercury in its own limb. B is 2.5 m above the mercury level in limb A.
a) 12.7 cm
b) 25.5 cm
c) 6.28 cm
d) 10.85 cm
. - An inverted differential manometer is connected to two pipes A and B which covey water. The fluid in manometer is oil of specific gravity 0.75. For the manometer readings, find the pressure difference between A and B. Datum in left limb is 40 cm above point A. Point B is 60 cm below datum line. Difference in level of fluid is 20 cm.
a) 1471 N/m2
b) 2943 N/m2
c) 735.75 N/m2
d) None of the mentioned
. - In the inverted U-tube Differential manometer, how is the specific gravity of manometric fluid used relative to the fluid flowing in the pipes
a) Specific gravity is more than that of fluid flowing in pipes
b) Specific gravity is less than that of fluid flowing in pipes
c) Specific gravity is equal to that of fluid flowing in pipes
d) None of the mentioned
. - Why is large reservoir used in single column manometer?
a) In order to enhance the change in level of liquid in reservoir
b) In order to negate the effects of change in level due to pressure variation
c) In order to reduce the effect due to dynamic pressure variation due to motion
d) None of the mentioned
. - Manometers are the pressure measuring devices which use the principle of dynamic pressure to measure the pressure difference.
a) True
b) False
. - The distance moved by liquid will be more in which type of manometer?
a) Inclined Single coloumn manometer
b) Vertical Single coloumn manometer
c) Horizontal Single coloumn manometer
d) None of the mentioned
. - Differential manometer gives the pressure reading with respect to atmospheric pressure.
a) True
b) False
. - Which device is popularly used for measuring difference of low pressure?
a) Inverted U-tube Differential Manometer
b) U-tube Differential Manometer
c) Inclined Single column manometer
d) Vertical Single column manometer
This set of Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Manometer”. - In a stationary fluid, how does the local pressure of the fluid vary?
a) With depth only
b) In the horizontal direction only
c) Both with depth and along horizontal direction
d) Neither with depth nor along horizontal direction
. - Which of the following cannot be the value of absolute pressure of a fluid at any point?
a) 0
b) 1.013 bar
c) – 1 bar
d) 200 bar
. - A student wants to find the absolute pressure of water at a point below the surface of water. He has a barometer and a manometer pressure gauge. The barometer reads 1.3152 bar where as the manometer pressure gauge reads 0.3152 bar. What is the absolute pressure? (Assume that pressure at one end of the manometer is atmospheric.)
a) 1 bar
b) 1.6304 bar
c) 0.3152 bar
d) 1.3152 bar
. - In a U-tube manometer, one end is open to the atmosphere, the other end attached to a pressurized gas of gauge pressure 40 kPa. The height of the fluid column in the atmospheric side is 60 cm, and that on the gas side is 30 cm. The manometic fluid used is: (Take g = 9.8 m/s2).
a) Water
b) Liquid ammonia
c) Oil
d) Mercury
. - In a U-tube mercury manometer, one end is exposed to the atmosphere and the other end is connected to a pressurized gas. The gauge pressure of the gas is found to be 40 kPa. Now, we change the manometric fluid to water. The height difference changes by: (ρmercury = 13600 kg/m3, ρwater = 1000 kg/m3).
a) 1260%
b) 92.64 %
c) Remains unchanged (0%)
d) 13.6%
. - A manometric liquid should suitably have _
a) Low density & Low Vapour pressure
b) Low density & High Vapour pressure
c) High density & Low Vapour pressure
d) High density & High Vapour pressure
. - A simple U-tube manometer can measure negative gauge pressures.
a) True
b) False
. - Both ends of a U-tube manometer are exposed to the atmosphere. There exists a possibility that the height difference of the manometer is non-zero. True or False?
a) True
b) False
.
9.The below figure shows an inclined U-tube mercury manometer. The vertical end of the tube is exposed to a gas of gauge pressure 50 kPa and the inclined end is exposed to the atmosphere. The inclined part of the tube is at an angle of 30o with the horizontal. Find the value of h (in cm) (take g = 9.8 m/s2, ρmercury = 13600 kg/m3)
a) 60
b) 50
c) 75
d) 25
.
- In the manometer given above, 2 immiscible fluids mercury (ρ = 13600 kg/m3) and water (ρ = 1000 kg/m3) are used as manometric fluids. The water end is exposed to atmosphere (100 kPa) and the mercury end is exposed to a gas. At this position, the interface between the fluids is at the bottom most point of the manometer. Ignore the width of the manometer tube and the radius of curvature. The value of h is found to be 9.45 m. The height of the mercury column is given to be 75 cm. Find the gauge pressure of the gas. (g = 9.8 m/s2)
a) 100 kPa
b) 50 kPa
c) 200 kPa
d) 0 kPa
- Find the position of centre of buoyancy for a wooden block of width 3.5 m and depth 1 m, when it floats horizontally in water. The density of wooden block id 850 kg/m3 and its length 7.0 m.
a) 0.95
b) 0.85
c) 1.05
d) 1.65
. - A stone weighs 450 N in air and 200 N in water. Compute the volume of stone.
a) .025 m3
b) .05 m3
c) .075 m3
d) None of the mentioned
. - A stone weighs 650 N in air and 275 N in water. Compute its specific gravity.
a) 1.73
b) 2.45
c) 3.46
d) 0.865
. - A body of dimensions 2.7 m * 3.8 m * 2.5 m, weighs 2500 N in water.Find its weight in air.
a) 254.12 kN
b) 508.25 kN
c) 101.65 kN
d) 127.06 kN
. - Find the density of metallic body which floats at the interface of mercury of sp.gr 13.6 and water such that 40 % of its volume is sub-merged in mercury and 60% in water.
a) 6040 kg/m3
b) 12080 kg/m3
c) 24160 kg/m3
d) 3020 kg/m3
. - What is the principal cause of action of buoyant force on a body submerged partially or fully in fluid?
a) Displacement of fluid due to submerged body
b) Development of force due to dynamic action
c) Internal shear forces mitigating external forces
d) None of the mentioned
. - How can relatively denser object be made to float on the less dense fluid?
a) By altering the shape.
b) By altering the forces acting on the object
c) By altering the shear forces acting on the object
d) None of the mentioned
. - What happens to the buoyant force acting on the airship as it rises in the air?
a) Buoyant force increases
b) Buoyant force decreases
c) Buoyant force remains constant
d) Buoyant force first increases then shows decrease
. - As a balloon rises in the air its volume increases, at the end it acquires a stable height and cannot rise any further.
a) True
b) False
. - Submarines use principle of ‘neutral buoyancy’ to go into the water.
a) True
b) False
This set of Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Metacentre and Metacentric Height”. - A rectangular pontoon is 5 m long, 3 m wide and 1.40 m high. The depth of immersion of the pontoon is 0.60 m in seawater. If the centre of gravity is 0.7 m above the bottom of the pontoon, determine the metacentric height. The density for seawater = 1045 kg/m3.
a) 0.135
b) 0.271
c) 0.543
d) 0.068
. - A uniform body of size 4 m long * 2.5 m wide * 1.5 m deep floats in water. What is the weight of the body if depth of immersion is 1 m ?
a) 147.1 kN
b) 294.3 kN
c) 73.5 kN
d) 588.6 kN
. - A block of material of specific gravity 0.45 floats in water. Determine the meta-centric height of the block if its size is 3 m * 2 m* 0.8 m.
a) 0.506 m
b) 0.376 m
c) 1.012 m
d) 0.127 m
. - A solid cylinder of diameter 4.5 has a height of 2.5 metres. Find the meta-centric height of the cylinder when it is floating in water with its axis vertical. The sp. gr. of the cylinder=0.45.
a) 1.9 m
b) 3.8 m
c) 5.7 m
d) .95 m
. - In case of spherically shaped bodies of uniform mass distribution and completely immersed in fluid and floating, the centre of buoyancy coincides with centre of gravity.
a) True
b) False
. - Proper explanation for metacentre is:
a) Point at which line of action of force meets the normal axis of body when it is given angular displacement
b) Intersection of line passing through new centre of buoyancy and centre of gravity.
c) point about which body starts oscillating when it is given small angular displacement
d) All of the mentioned
. - The metacentric height is affected by the change in density.
a) True
b) False
.
8.For a completely immersed body, the metacentric height is always zero.
a) True
b) False
. - Meta centre always lies below the centre of gravity
a) True
b) False
. - The principle of floatation of bodies is based on the premise of
a) Metacentre
b) Newtons first law
c) Newtons law of viscosity
d) None of the mentioned
