Hydraulics And Fluid Mechanics Set 9 MCQs

Q1 | The velocity of the liquid flowing through the divergent portion of a Venturimeter

Remains constant

Increases

Decreases

Depends upon mass of liquid

Q2 | The volumetric change of the fluid caused by a resistance is known as

Volumetric strain

Volumetric index

Compressibility

Adhesion

Q3 | If the depth of water in an open channel is less than the critical depth, the flow is called

Critical flow

Turbulent flow

Tranquil flow

Torrential flow

Q4 | Choose the wrong statement

Fluids are capable of flowing

Fluids conform to the shape of the containing vessels

When in equilibrium, fluids cannot sustain tangential forces

When in equilibrium, fluids can sustain shear forces

Q5 | An orifice is said to be large, if

The size of orifice is large

The velocity of flow is large

The available head of liquid is more than 5 times the height of orifice

The available head of liquid is less than 5 times the height of orifice

Q6 | A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?

The metal piece will simply float over the mercury

The metal piece will be immersed in mercury by half

Whole of the metal piece will be immersed with its top surface just at mercury level

Metal piece will sink to the bottom

Q7 | The centre of pressure acts __________ the centre of gravity of immersed surface.

At

Above

Below

None of these

Q8 | Dynamic viscosity of most of the liquids with rise in temperature

Increases

Decreases

Remain unaffected

Unpredictable

Q9 | The discharge over a right angled notch is (where H = Height of liquid above the apex of notch)

(8/15) Cd. 2g. H

(8/15) Cd. 2g. H3/2

(8/15) Cd. 2g. H²

(8/15) Cd. 2g. H5/2

Q10 | A square surface 3 m × 3 m lies in a vertical line in water pipe its upper edge at water surface. The hydrostatic force on square surface is

9,000 kg

13,500 kg

18,000 kg

27,000 kg

Q11 | Select the correct statement

Local atmospheric pressure depends upon elevation of locality only

Standard atmospheric pressure is the mean local atmospheric pressure a* sea level

Local atmospheric pressure is always below standard atmospheric pressure

A barometer reads the difference between local and standard atmospheric pressure

Q12 | The shear stress-strain graph for a Newtonian fluid is a

Straight line

Parabolic curve

Hyperbolic curve

Elliptical

Q13 | The flow in which the particles of a fluid attain such velocities that varies from point to point in magnitude and direction as well as from instant to instant, is known as

One dimensional flow

Uniform flow

Steady flow

Turbulent flow

Q14 | Uniform flow occurs when

The direction and magnitude of the velocity at all points are identical

The velocity of successive fluid particles, at any point, is the same at successive periods of time

The magnitude and direction of the velocity do not change from point to point in the fluid

The fluid particles move in plane or parallel planes and the streamline patterns are identical in each pleasure

Q15 | At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be

Minimum

Maximum

Zero

Could be any value

Q16 | The discharge through a channel of trapezoidal section is maximum when

Width of channel at the top is equal to twice the width at the bottom

Depth of channel is equal to the width at the bottom

The sloping side is equal to half the width at the top

The sloping side is equal to the width at the bottom

Q17 | Piezometer is used to measure

Pressure in pipe, channels etc.

Atmospheric pressure

Very low pressures

Difference of pressure between two points

Q18 | The point at which the resultant pressure on an immersed surface acts, is known as

Centre of gravity

Centre of depth

Centre of pressure

Centre of immersed surface

Q19 | Choose the wrong statement

Any weight, floating or immersed in a liquid, is acted upon by a buoyant force

Buoyant force is equal to the weight of the liquid displaced

The point through which buoyant force acts, is called the center of buoyancy

Center of buoyancy is located above the center of gravity of the displaced liquid

Q20 | The pressure in the air space above an oil (sp. gr. 0.8) surface in a tank is 0.1 kg/cm". The pressure at 2.5 m below the oil surface will be

2 metres of water column

3 metres of water column

3.5 metres of water column

4 m of water column

Q21 | The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is

Directly proportional to (radius)2

Inversely proportional to (radius)2

Directly proportional to (radius)4

Inversely proportional to (radius)4

Q22 | The flow which neglects changes in a transverse direction is known as

One dimensional flow

Uniform flow

Steady flow

Turbulent flow

Q23 | The mass per unit volume of a liquid at a standard temperature and pressure is called

Specific weight

Mass density

Specific gravity

None of these

Q24 | A large Reynold number is indication of

Smooth and streamline flow

Laminar flow

Steady flow

Highly turbulent flow

Q25 | Which of the following statement is wrong?

A flow whose streamline is represented by a curve is called two dimensional flow.

The total energy of a liquid particle is the sum of potential energy, kinetic energy and pressure energy.

The length of divergent portion in a Venturimeter is equal to the convergent portion.

A pitot tube is used to measure the velocity of flow at the required point in a pipe.