1. Choose the correct answer from the given four alternatives.

A fluid is a substance that

cannot withstand any shear force.

cannot remain at rest under the action of a shear force.

flows in the absence of external forces.

is incompressible and inviscid.

A solid body sinks in a fluid when

the specific gravity of its material is greater than unity.

the buoyancy force does not pass through the metacentre.

the weight of the fluid displaced is less than the weight of the body.

the metacentre lies below the centre of gravity.

For two pipes arranged in series,

the flow may be different in different pipes.

the head loss per unit length must be more in a smaller pipe.

the velocity must be the same in all pipes.

the head loss must be the same in all pipes.

The Reynolds number is defined as the ratio of

gravity force to viscous force

viscous force to inertia force

inertia force to viscous force

gravity force to inertia force

Select the correct statement.

Viscosity of a gas increases with temperature.

Density of a gas increases with temperature.

Surface tension of a liquid increases with temperature.

Bulk modulus of elasticity is independent of temperature.

The buoyant force acting on a floating body passes through the

metacentre of the body

centre of gravity of the body

centroid of volume of the body

centroid of the displaced volume

Of the various methods of measuring discharge through a pipeline, the one with the least loss of energy and direct reading is

by means of a venturimeter

by means of an orifice meter

by means of a flow nozzle

by traversing a pitot-static probe

2. Answer any two of the following:

Define the terms and Explain the classification of the fluid flow on the basis of the fluid properties and the flow phenomena.

If the velocity distribution over a plate is given by



where u is the velocity in m/s at distance y metres above the plate, determine the shear stress at a distance of 0·15 m from the plate. Take the dynamic viscosity of the fluid as 0·834 Ns/m^2.

What percentage of an iceberg floats visibly above the sea level, if the density of the iceberg is 900 kglm3 and the density of sea water is 1020 kg/m^3

3. Answer any two of the following:

Describe Reynolds experiment on flow through pipes.

An open tank contains water up to a depth of 1·5 m and above it an oil of specific gravity 0·8 for a depth of 2 m. Find the pressure

at the interface of the two liquids, and

at the bottom of the tank.

The diameters of a small piston and a large piston of a hydraulic jack are 2 cm and 10 cm, respectively. A force of 60 N is applied on the small piston. Find the load lifted by the large piston, when

the pistons are at the same level, and

the small piston is 20 cm above the large piston.

The density of the liquid in the jack is given as 1000 kg/m^3.

4. Answer any two of the following:

Define the following coefficients:

Coefficient of velocity

Coefficient of contraction

Coefficient of discharge

A 25 mm diameter nozzle discharges 0·76 m^3 of water per minute when the head is 60 m. The diameter of the jet is 22.5 mm. Determine the values of coefficients Cc, Cv and Cd.

Find the loss of head when a pipe of diameter 200 mm is suddenly enlarged to a diameter of 400 mm. The rate of flow of water through the pipe is 250 litres/see.

5. Write short notes on any four of the following:

Bulk Modulus

Laminar Flow

Unsteady Flow

Cavitation

Hydraulic Gradient Line

Water Hammer