Hydraulics And Fluid Mechanics Set 2 MCQs

Q1 | An object having 10 kg mass weighs 9.81 kg on a spring balance. The value of 'g' at this place is

10 m/sec²

9.81 m/sec²

9.75 m/sec²

9 m/sec

Q2 | A flow is called hyper-sonic, if the Mach number is

Less than unity

Unity

Between 1 and 6

None of these

Q3 | Liquids

Cannot be compressed

Occupy definite volume

Are not affected by change in pressure and temperature

None of the above

Q4 | When a cylindrical vessel containing liquid is resolved, the surface of the liquid takes the shape of

A triangle

A paraboloid

An ellipse

None of these

Q5 | Fluid is a substance that

Cannot be subjected to shear forces

Always expands until it fills any container

Has the same shear stress at a point regardless of its motion

Cannot remain at rest under action of any shear force

Q6 | The force exerted by a moving fluid on an immersed body is directly proportional to the rate of change of momentum due to the presence of the body. This statement is called

Newton's law of motion

Newton's law of cooling

Newton's law of viscosity

Newton's law of resistance

Q7 | The property of a fluid which enables it to resist tensile stress is known as

Compressibility

Surface tension

Cohesion

Adhesion

Q8 | The loss of pressure head in case of laminar flow is proportional to

Velocity

(Velocity)2

(Velocity)3

(Velocity)4

Q9 | The surface tension of mercury at normal temperature compared to that of water is

More

Less

Same

More or less depending on size of glass tube

Q10 | An air vessel is provided at the summit in a siphon to

Avoid interruption in the flow

Increase discharge

Increase velocity

Maintain pressure difference

Q11 | The unit of viscosity is

Metres² per sec

kg-sec/metre

Newton-sec per metre²

Newton-sec per meter

Q12 | Select the correct statement

Weber's number is the ratio of inertia force to elastic force.

Weber's number is the ratio of gravity force to surface tension force.

Weber's number is the ratio of viscous force to pressure force.

Weber's number is the ratio of inertia force to surface tension force.

Q13 | Choose the wrong statement. Alcohol is used in manometer, because

Its vapour pressure is low

It provides suitable meniscus for the inclined tube

Its density is less

It provides longer length for a given pressure difference

Q14 | When a tank containing liquid moves with an acceleration in the horizontal direction, then the free surface of the liquid

Remains horizontal

Becomes curved

Falls on the front end

Falls on the back end

Q15 | A pressure of 25 m of head of water is equal to

25 kN/ m²

245 kN/ m²

2500 kN/m²

2.5 kN/ m²

Q16 | The hammer blow in pipes occurs when

There is excessive leakage in the pipe

The pipe bursts under high pressure of fluid

The flow of fluid through the pipe is suddenly brought to rest by closing of the valve

The flow of fluid through the pipe is gradually brought to rest by closing of the valve

Q17 | The resultant upward pressure of the fluid on an immersed body is called

Up-thrust

Buoyancy

Center of pressure

All the above are correct

Q18 | When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as

Narrow-crested weir

Broad-crested weir

Ogee weir

Submerged weir

Q19 | If the surface of liquid is convex, men

Cohesion pressure is negligible

Cohesion pressure is decreased

Cohesion pressure is increased

There is no cohesion pressure

Q20 | The atmospheric pressure with rise in altitude decreases

Linearly

First slowly and then steeply

First steeply and then gradually

Unpredictable

Q21 | Dynamic viscosity of most of the gases with rise in temperature

Increases

Decreases

Remain unaffected

Unpredictable

Q22 | According to Bernoulli's equation

Z + p/w + v²/2g = constant

Z + p/w - v²/2g = constant

Z - p/w + v²/2g = constant

Z - p/w - v²/2g = constant

Q23 | Newton's law of viscosity is a relationship between

Pressure, velocity and temperature

Shear stress and rate of shear strain

Shear stress and velocity

Rate of shear strain and temperature

Q24 | Differential manometer is used to measure

Pressure in pipes, channels etc.

Atmospheric pressure

Very low pressure

Difference of pressure between two points

Q25 | Non 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

Velocity, depth, pressure, etc. change from point to point in the fluid flow.

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