Hydraulics And Fluid Mechanics Set 6 MCQs

Q1 | The center of pressure of a surface subjected to fluid pressure is the point

On the surface at which resultant pressure acts

On the surface at which gravitational force acts

At which all hydraulic forces meet

Similar to metacentre

Q2 | The variation in the volume of a liquid with the variation of pressure is called its

Surface tension

Compressibility

Capillarity

Viscosity

Q3 | The surface tension of mercury at normal temperature is __________ that of water.

Same as

Lower than

Higher than

None of these

Q4 | Flow of water in a pipe about 3 metres in diameter can be measured by

Orifice plate

Venturimeter

Rotameter

Pitot tube

Q5 | According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)

(2/3) × Cd (L - nH) ×

(2/3) × Cd (L - 0.1nH) × × H3/2

(2/3) × Cd (L - nH) × × H²

(2/3) × Cd (L - nH) × × H5/2

Q6 | The equation of continuity holds good when the flow

Is steady

Is one dimensional

Velocity is uniform at all the cross sections

All of the above

Q7 | A thick liquid like syrup has a __________ viscosity than a light liquid like water.

Lesser

Greater

Same

None of these

Q8 | Cavitation will begin when

The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid

Pressure becomes more than critical pressure

Flow is increased

Pressure is increased

Q9 | When a liquid is flowing through a pipe, the velocity of the liquid is

Maximum at the centre and minimum near the walls

Minimum at the centre and maximum near the walls

Zero at the centre and maximum near the walls

Maximum at the centre and zero near the walls

Q10 | The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.

0.34 times

0.67 times

0.81 times

0.95 times

Q11 | Resultant pressure of the liquid in the case of an immersed body acts through

Centre of gravity

Centre of pressure

Metacentre

Centre of buoyancy

Q12 | A fluid is said to be ideal, if it is

Incompressible

Viscous and incompressible

Inviscous and compressible

Inviscous and incompressible

Q13 | In a depressed nappe

The pressure below the nappe is atmospheric

The pressure below the nappe is negative

The pressure above the nappe is atmospheric

The pressure above the nappe is negative

Q14 | The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to

2100

2700

10,000

21,000

Q15 | In one dimensional flow, the flow

Is steady and uniform

Takes place in straight line

Takes place in curve

Takes place in one direction

Q16 | To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than

2.4 m above the hydraulic gradient

6.4 m above the hydraulic gradient

10.0 m above the hydraulic gradient

5.0 above the hydraulic gradient

Q17 | The loss of head at exit of a pipe is (where v = Velocity of liquid in the pipe)

v²/2g

0.5v²/2g

0.375v²/2g

0.75v²/2g

Q18 | Metacentre is the point of intersection of

Vertical upward force through e.g. of body and center line of body

Buoyant force and the center line of body

Midpoint between e.g. and center of buoyancy

All of the above

Q19 | The imaginary line drawn in the fluid in such a way that the tangent to any point gives thedirection of motion at that point, is known as

Path line

Stream line

Steak line

Potential line

Q20 | An open vessel of water is accelerated up an inclined plane. The free water surface will

Be horizontal

Make an angle in direction of inclination of inclined plane

Make an angle in opposite direction to inclination of inclined plane

Any one of above is possible

Q21 | The discharge over a rectangular notch is

Inversely proportional to H3/2

Directly proportional to H3/2

Inversely proportional to H5/2

Directly proportional to H5/2

Q22 | The flow in which each liquid particle has a definite path and their paths do not cross each other is called

One dimensional flow

Streamline flow

Steady flow

Turbulent flow

Q23 | The magnitude of water hammer depends upon the

Elastic properties of the pipe material

Elastic properties of the liquid flowing through the pipe

Speed at which the valve is closed

All of the above

Q24 | The fluid forces considered in the Navier Stokes equation are

Gravity, pressure and viscous

Gravity, pressure and turbulent

Pressure, viscous and turbulent

Gravity, viscous and turbulent

Q25 | Cavitation is caused by

High velocity

High pressure

Weak material

Low pressure