HYDRAULICS Reference Guide

Pipe Flow

The loss of head due to friction according to Darcy's formula is
a) fLv/2gd
b) 4fLv²/2gd
c) fLv²/gd
d) 4fLv²/2gd

The T.E.L. lies over the H.G.L. by an amount equal to
a) p/ρg
b) v²/2g
c) v²/2g + p/ρg
d) z

The hydraulic mean depth for a circular pipe is
a) D/2
b) D/3
c) D/4
d) D/π

The loss of head due to sudden enlargement is given by
a) 0.5v₁²/2g
b) (v₁+v₂)²/2g
c) (v₁-v₂)²/2g
d) (v₁²-v₂²)/2g

The loss of head at the exit is
a) 0.5v²/2g
b) v²/g
c) v²/2g
d) 2v²/g

The relation between friction factor and coefficient of friction (Cf) is given by
a) Cf = f
b) Cf = 2f
c) Cf = f/2
d) Cf = 4f

Loss of head due to friction in pipe is given by
a) Bernoulli's equation
b) Continuity equation
c) Manning's equation
d) Darcy-Weisbach equation

A compound pipe is required to be replaced by a new pipe. The pipes are said to be equivalent if both of them have same
a) length and diameter
b) loss of head
c) discharge
d) both 'b' and 'c'

In case of parallel pipes
a) loss of head for all pipes is same
b) total discharge is equal to sum of discharge in all pipes
c) Total loss of head is equal to the sum of loss of heads in all the pipes
d) Both 'a' and 'b'

For pipes arranged in series
a) The head loss must be same in all the pipes
b) The velocity must be same in all pipes
c) The flow may be different in different pipes
d) The total flow is same flowing through each pipe

Pipes are arranged in parallel to
a) increase discharge
b) decrease head loss
c) decrease discharge
d) reduce length of pipe

The power transmitted through a pipe is maximum when the head loss due to friction is equal to
a) H/6
b) H/4
c) H/3
d) H/2

The difference between the total head line and the hydraulic grade line represents the:
A. Piezometric head
B. Pressure head
C. Elevation head
D. Velocity head

The frictional resistance for fluids in motion is:
A. proportional to velocity in laminar flow and to square of the velocity in turbulent flow
B. proportional to square of the velocity in laminar flow and to the velocity in turbulent flow
C. proportional to velocity in both laminar flow & turbulent flow
D. proportional to square of the velocity in both laminar flow & turbulent flow

The property of the fluid that accounts for the major losses in pipes is
a) density
b) specific gravity
c) viscosity
d) compressibility

When the Reynold's number is less than 500, the flow is said to be laminar for
a) pipe flow
b) flow between parallel plates
c) free surface flow
d) none of the above

When a fluid flows through a tapering pipe at a constantly increasing rate, the flow is said to be
a) Turbulent flow
b) Unsteady uniform flow
c) Unsteady non-uniform flow
d) Irrotational flow

The head loss through fluid flowing in a pipe due to friction is
a) the minor loss
b) the major loss
c) both a and b
d) none of the above

The frictional resistance for fluids in motion is
a) dependent on the pressure for both laminar and turbulent flows
b) independent of the pressure for both laminar and turbulent flows
c) dependent on the pressure for laminar flow and independent of the pressure for turbulent flow
d) independent of the pressure for laminar flow and dependent on the pressure for turbulent flow

The vertical intercept between EGL and HGL is equal to
a) pressure head
b) potential head
c) kinetic head
d) Piezometric head

Pipe Networks

If three pipes are connected in series, then
a) head loss is the same for all
b) discharge is the same for all
c) friction factor is the same for all
d) velocity is the same for all

What is the total loss developed in a series of pipes?
a) Sum of losses in each pipe only
b) Sum of local losses only
c) Sum of local losses plus the losses in each pipe
d) Zero

Unsteady Flow

During the opening of a valve in a pipeline, the flow is
a) Steady
b) Unsteady
c) Uniform
d) Laminar

Open Channel Flow

The hydraulic radius of a rectangular open channel having a width of 4m and a depth of 1.5m is:

A. 0.857m
B. 1.230m
C. 1.152m
D. 0.595m

For obtaining the most economical trapezoidal channel section with a depth of flow = 3m, the hydraulic mean radius is:

A. 1.5m
B. 3.0m
C. 2.0m
D. 1.0m

A rectangular channel of bed width 2m is to be laid at a bed slope of 1 in 1000. The hydraulic radius of the canal cross-section for the maximum discharge condition is:

A. 0.5m
B. 2m
C. 1m
D. 0.25m

The ratio of Hydraulic radius to Hydraulic depth is h, and the top width of the channel is 6m. The hydraulic depth of the rectangular channel is:

A. 1 m
B. 2 m
C. 3 m
D. 4 m

Uniform Flow

Energy & Momentum

Gradually Varied Flow

Hydraulic Jump

During a steady jump, the value of Froude lies in between——-

A. 1 to 2.5
B. 2.5 to 4.5
C. Less than 1
D. 4.5 to 9

The depth of water below the spillway and after the hydraulic jump are 1 m and 6 m, respectively. The head loss will be:

A. 1.04 m
B. 5 m
C. 1.7 m
D. 2.05 m

Mobile Boundary

Calculate the critical shear stress for usual turbulent flow, given a mean diameter of grain particles in the bed material of 0.3 mm:

A. 0.300 N/m²
B. 0.100 N/m²
C. 0.206 N/m²
D. 0.116 N/m²

Similitude

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