WorksheetsHydraulics MCQ Practice Questions
Total questions: 50
Worksheet time: 25mins
A pipe is defined as:
An open channel for flow under gravity
A closed conduit carrying fluid under pressure
A venturi device used to measure discharge
A porous medium used in seepage flow
Loss of head due to bends, valves, and other fittings in a pipe are categorized as:
Major losses
Minor losses
Primary losses
Secondary losses
The Darcy–Weisbach equation is used to calculate:
Head loss due to friction
Minor losses in a pipe
Velocity distribution in a pipe
Pressure drop due to contraction
In Darcy–Weisbach equation, the friction factor “f”:
Depends only on pipe length
Is always constant for all pipes
Depends on Reynolds number and pipe roughness
Is independent of flow conditions
Chezy’s equation relates:
Pressure head and velocity head
Pipe diameter and velocity
Head loss and discharge
Velocity, hydraulic radius, and bed slope
The expression of head loss due to sudden enlargement is:
V^2 / 2g
V1^2 − V2^2 / 2g
4flV^2 / 2gd
k*V^2 / 2g
The expression of head loss due to sudden contraction is:
V^2 / 2g
V1^2 − V2^2 / 2g
4flV^2 / 2gd
k*V^2 / 2g
The major loss of head in a long pipe is due to:
Sudden enlargement
Friction between fluid and pipe wall
Sudden contraction
Valves and bends
In pipes connected in series, which of the following is true?
Head loss is the same in each pipe
Discharge is the same through all pipes
Velocity is the same in each pipe
None of the above
In pipes connected in parallel:
Discharge remains same in all branches
Pipe diameters must be equal
Velocity is constant in all branches
Head loss is same in all parallel branches
Which one of the following equations gives velocity of flow in Chezy’s formula?
V=Q/A
V = C√(mi)
V=v1−v2/2g
V=√(2gℎ/1+k)
The total head loss in a pipeline system is:
Only due to friction
Only due to bends and fittings
Sum of major and minor losses
Only due to sudden enlargement
In Darcy’s equation, if the length of the pipe is doubled, the head loss due to friction becomes:
Half
Double
Four times
Unchanged
The hydraulic gradient in Chezy’s equation refers to:
Loss of head per unit length of pipe
Ratio of velocity to diameter
Ratio of discharge to wetted perimeter
Loss of energy due to fittings
If two identical pipes are connected in parallel between two reservoirs, the total discharge will be:
Equal to discharge through one pipe
Half the discharge through one pipe
Double the discharge through one pipe
Zero
Formula for discharge through a triangular notch is___________
Qa= 8/15×Cd ×√(2g)×tan〖θ/2〗×H^(3/2)
Qa= 8/15× Cd ×√(2g)×tan〖θ/2〗×H^(5/2)
Qa= 15/8×Cd×√((2g) )×tan〖θ/2〗×H^(3/2)
Qa= 8/15×Cd ×√(2g)×tan〖θ/2〗×H^(2/5)
A notch is defined as:
An obstruction in a pipe to measure velocity
An opening in the side of a tank or reservoir with liquid surface below crest
A dam constructed across a river
A device to measure pressure head
A weir is defined as:
A small hole in a tank to measure discharge
A structure constructed across a river or channel to measure or control flow
A sharp-edged notch cut in a tank wall
A device for measuring velocity in a pipe
The main difference between a notch and a weir is:
Notches are made in tanks, weirs are built across rivers/channels
Weirs are always triangular, notches are always rectangular
Notches measure velocity, weirs measure pressure
Weirs are temporary, notches are permanent
For the same head, the discharge through a triangular notch is:
Less than rectangular notch
More than rectangular notch
Equal to rectangular notch
Independent of notch angle
The discharge formula for a trapezoidal notch is:
Sum of rectangular notch discharge and triangular notch discharge
Difference of rectangular and triangular notch discharge
Only rectangular discharge formula
Only triangular discharge formula
For measuring discharge through triangular notch, which of the following characteristics are needed?
Angle of the notch (θ) and width of the notch
Angle of the notch(θ) and head over the notch (H)
Width of the notch(b) and head over the notch (H)
Angle of the notch(θ) only
Formula for discharge through a rectangular notch is
Qa= 2/3×Cd ×√(2g)×b×H^(3/2)
Qa = 3/2×Cd ×√(2g)×b×H^(3/2)
Qa = 2/3×Cd ×√(2g)×b×H^(2/3)
Qa = 2/3×Cd ×√(2g)×b×H^(5/2)
Rectangular notch discharge varies as:
H^2
H^5/2
H^3/2
H^8/15
Triangular notch discharge varies as:
H^2
H^5/2
H^3/2
H^8/15
Which type of weir is commonly used in irrigation channels?
Ogee weir
Broad-crested weir
Sharp-crested weir
Cipoletti weir
A trapezoidal notch is also known as:
Bazin’s notch
Cipoletti notch
Francis notch
Venturi notch
The coefficient of discharge (C_d) for notches accounts for:
Pressure loss only
Velocity of approach only
Both velocity of approach and contraction
Area of opening
V-notch is preferred over rectangular notch because:
It is easier to construct
It is more accurate for small discharges
It requires no coefficient of discharge
It is stronger in structure
Which of the following is not a classification of weirs?
Sharp-crested
Broad-crested
Ogee
Square-crested notch
A pump is defined as a device which converts:
Mechanical energy to hydraulic energy
Electrical energy to hydraulic energy
Electrical energy to mechanical energy
Hydraulic energy to mechanical energy
A single-acting reciprocating pump delivers fluid:
During both strokes
Only during one stroke of the piston
Continuously without fluctuation
Only at the suction stroke
A double-acting reciprocating pump delivers fluid:
In only one direction
During both forward and return strokes
With more slip than single-acting pump
Only during suction
The difference between theoretical discharge and actual discharge in reciprocating pumps is called:
Slip
Priming
Cavitation
Head loss
Negative slip in a reciprocating pump occurs when:
Actual discharge is less than theoretical discharge
Actual discharge equals theoretical discharge
Actual discharge is more than theoretical discharge
Pump runs without priming
The purpose of an air vessel in reciprocating pumps is to:
Reduce friction in the piston
Smoothen flow and reduce fluctuations in discharge
Increase velocity of water
Prime the pump
Priming in centrifugal pumps is done to:
Remove air from casing and fill it with liquid
Increase velocity of impeller
Reduce slip in delivery pipe
Improve suction lift
In centrifugal pumps, the foot valve is used to:
Control delivery of liquid
Prevent return of liquid to the sump during off conditions
Measure pressure head
Reduce friction loss
The non-return valve in a pump is used to:
Allow water to flow only in one direction
Allow water to flow in both directions
Stop water hammer completely
Increase velocity of water
Which one of the following is an advantage of centrifugal pumps over reciprocating pumps?
Higher efficiency for small discharge
Continuous and uniform discharge
Less priming required always
More slip at high speed
Cavitation in centrifugal pumps is caused by:
Very high discharge
Pressure in suction pipe falling below vapor pressure
High delivery head
Large slip
The characteristics curve of a centrifugal pump represents relation between:
Head, discharge, power and efficiency
Slip, speed and suction head
Air vessel, suction lift and priming
Discharge, velocity and pipe friction
Efficiency of a pump is defined as
Ratio of output power to input power
Ratio of input power to output power
Ratio of useful work done to the energy supplied
Difference between actual discharge and theoretical discharge
At the best efficiency point (BEP) of a centrifugal pump characteristic curve:
Pump operates at maximum efficiency with stable operation
Slip is maximum
Power required is minimum but discharge is zero
Suction head is maximum
Reciprocating pumps are generally used for:
High discharge, low head applications
Low discharge, high head applications
Irrigation fields
Circulating water in power plants
Which type of pump is commonly used in household water supply systems?
Reciprocating pump
Centrifugal pump
Gear pump
Jet pump
Centrifugal pumps are most suitable for:
Small discharge and high heads
Hydraulic Jacks
Compressing air in industries
Large discharge and low to medium heads
Which of the following is not a positive displacement pump?
Centrifugal pump
Reciprocating pump
Gear pump
Vane pump
Which of the following is not a rotodynamic pump?
Centrifugal pumps
Propeller pumps
Screw pumps
Reciprocating pump
The efficiency of a pump can be affected by
Slip
Pump speed
Fluid temperature
All of the above
