MHADA Exam Technical Question MCQ Mock Test 53

1➤ Pascal-second is the unit of

pressurekinematic viscositydynamic viscositysurface tension

2➤ An ideal fluid is

frictionless and incompressibleone which obeys Newton’s law of viscosityvery viscousfrictionless and compressible

3➤ The unit of kinematic viscosity is

gm/cm-sec2dyne-sec/cm2gm/cm2-seccm2/sec

4➤ If the dynamic viscosity of a fluid is 0.5 poise and specific gravity is 0.5, then the kinematic viscosity of that fluid in stokes is

0.250.501.0none of the above

5➤ The viscosity of a gas

decreases with increase in temperatureincreases with increase in temperatureis independent of temperatureis independent of pressure for very high pressure intensities

6➤ Newton’s law of viscosity relates

intensity of pressure and rate of angular deformationshear stress, viscosity and temperatureshear stress and rate of angular deformationviscosity and rate of angular deformation

7➤ An open tank contains 1 m deep water with 50 cm depth of oil of specific gravity 0.8 above it. The intensity of pressure at the bottom of tank will be

4 kN/m210 kN/m212 kN/m214 kN/m2

8➤ The position of center of pressure on a plane surface immersed vertically in a static mass of fluid is

at the centroid of the submerged areaalways above the centroid of the areaalways below the centroid of the areanone of the above

9➤ The total pressure on a plane surface inclined at an angle 9 with the horizontal is equal to

PApA sin 9pA cos 9pA tan 9

10➤ A vertical rectangular plane surface is submerged in water such that its top and bottom surfaces are 1.5 m and 6.0 m res-pectively below the free surface. The position of center of pressure below the free surface will be at a distance of

3.75 m4.0 m4.2m4.5m

11➤ Centre of buoyancy always

coincides with the centre of gravityremains above the centre of gravityremains below the centre of gravitycoincides with the centroid of the volume of fluid displaced

12➤ If the weight of a body immersed in a fluid exceeds the buoyant force, then the body will

rise until its weight equals the buoyant forcetend to move downward and it may finally sinkfloatnone of the above

13➤ Metacentric height for small values of angle of heel is the distance between the

centre of gravity and centre of buoy-ancycentre of gravity and metacentrecentre of buoyancy and metacentrefree surface and centre of buoyancy

14➤ A floating body is said to be in a state of stable equilibrium

when the metacentre is above the centre of gravitywhen its metacentric height is zerowhen the metacentre is below the centre of gravityonly when its centre of gravity is below its centre of buoyancy

15➤ The increase in meta centric height i) increases stability ii) decreases stability iii) increases comfort for passengers iv) decreases comfort for passengers The correct answer is......

(i) and (iii)(i)and(iv)(ii) and (iii)(ii) and (iv)

16➤ A rectangular block 2 m long, 1 m wide and 1 m deep floats in water, the depth of immersion being 0.5 m. If water weighs 10 kN/m3, then the weight of the block is

5kN1OkN15 kN20 kN

17➤ The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as

center of gravitycenter of buoyancycenter of pressuremetacentre

18➤ If a vessel containing liquid moves downward with a constant acceleration equal to ‘g’ then

the pressure throughout the liquid mass is atmosphericthe pressure in the liquid mass is greater than hydrostatic pressurethere will be vacuum in the liquidnone of the above

19➤ When a liquid rotates at a constant angular velocity about a vertical axis as a rigid body, the pressure intensity varies

linearly with radial distanceas the square of the radial distanceinversely as the square of the radial distanceinversely as the radial distance

20➤ An open cubical tank of 2 m side is filled with water. If the tank is rotated with an acceleration such that half of the water spills out, then the acceleration is equal to

g/32g/3g/2g

21➤ A right circular cylinder open at the top is filled with liquid and rotated about its vertical axis at such a speed that half the liquid spills out, then the pressure intensity at the center of bottom is

zeroone-fourth its value when cylinder was fullone-half its value when cylinder was fullcannot be predicted from the given data

22➤ The horizontal component of force on a curved surface is equal to the

force on a vertical projection of the curved surfaceproduct of pressure intensity at its centroid and areaweight of liquid vertically above the curved surfaceforce on the horizontal projection of the curved surface

23➤ A closed tank containing water is moving in a horizontal direction along a straight line at a constant speed. The tank also contains a steel ball and a bubble of air. If the tank is decelerated horizontally, then i) the ball will move to the front ii) the bubble will move to the front iii) the ball will move to the rear iv) the bubble will move to the rear Find out which of the above statements are correct ?

(i) and (ii)(i) and (iv)(ii) and (iii)(iii) and (iv)

24➤ The eddy viscosity for turbulent flow is

a function of temperature onlya physical property of the fluiddependent on the flowindependent of the flow

25➤ Flow at constant rate through a tapering pipe is i) steady flow ii) uniform flow iii) unsteady flow iv) non-uniform flow The correct answer is

(i) and (ii)(i)and(iv)(ii) and (iii)(ii) and (iv)

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