Which energy is converted from water to develop hydroelectricity?
a) Potential Energy
b) Kinetic Energy
c) Both Potential and Kinetic Energy
d) None of these

c) Both Potential and Kinetic Energy
Explanation: In a typical hydropower plant, water stored at a height possesses gravitational potential energy. As it falls, this potential energy is converted into kinetic energy which then drives the turbine, ultimately generating electricity.

In hydropower generation, the generator converts:
a) Hydraulic energy into mechanical energy
b) Mechanical into elctrical energy
c) Hydraulic energy into electrical energy
d) None of these

b) Mechanical into elctrical energy
Explanation: Although the turbine converts the flowing water’s hydraulic (or kinetic) energy into mechanical energy, the generator then takes that mechanical energy and converts it into electrical energy. Here, option (c) captures the overall conversion process.

Hydropower is a:
a) Renewable Energy
b) Non-renewable Energy
c) Both of the above
d) None of these

Answer: a
Explanation: Hydropower uses the water cycle—a naturally recurring process—to generate electricity, making it a renewable source of energy.

Which of the following has the highest hydropower potential in Nepal?
a) Gross Potential
b) Technical Potential
c) Economical Potential
d) None of these

Answer: a
Explanation: Gross potential represents the total available energy from hydropower resources in Nepal, without considering practical constraints. Although technical and economical potentials narrow this number down, the gross potential remains the highest theoretical value.

Gross potential of Nepal is:
a) 83000 MW
b) 44000 MW
c) 42000 MW
d)None of these

a) 83000 MW
Explanation: Nepal’s gross hydropower potential is estimated to be around 83,000 MW, which represents the total theoretical capacity available from its water resources.

World's largest hydropower project is:
a) Upper Tamakoshi HEP
b) Itaipu Dam Project
c) Xiluodu Project
d) Three Gorges Project

Answer: d
Explanation: The Three Gorges Project in China is widely recognized as the world’s largest hydropower project by installed capacity.

Which region has the world's most hydropower potential?
a) Asia
b) Latin America
c) Europe
d) Africa

b) Latin America
Explanation: Latin America harbors immense hydropower resources because of its vast river systems and varied topography, making it the region with the most hydropower potential.

The Three Gorges Project has a capacity of:
a) 20000 MW
b) 21500 MW
c) 22500 MW
d) 22000 MW

Answer: c
Explanation: With an installed capacity of approximately 22,500 MW, the Three Gorges Dam stands as one of the largest hydropower projects in the world.

Nepal's largest storage hydropower project is:
a) Kulekhani-I HEP
b) Kulekhani-II HEP
c) Kulekhani-III HEP
d) Upper Tamakoshi HEP

a) Kulekhani-I HEP
Explanation: Among the cascade of Kulekhani projects, Kulekhani-I is recognized as Nepal’s largest storage hydropower plant, utilizing a reservoir to store water for energy generation.

Nepal's largest peaking hydropower based on capacity project is:
a) Kaligandaki 'A' HEP
b) Middle Marsyandi HEP
c) Marsyangdi HEP
d) Upper Tamakoshi HEP

Answer: d
Explanation: With an installed capacity of 456 MW, Upper Tamakoshi HEP stands out as the largest peaking hydropower project in Nepal.

Upper Tamakoshi HEP has a capacity with a peaking hour of:
a) 456 MW with 5 hrs Peaking
b) 456 MW with 4 hrs Peaking
c)456 MW with 6 hrs Peaking
d)456 MW with 3 hrs Peaking

Answer: b
Explanation: Upper Tamakoshi HEP is designed to operate at 456 MW with a 4-hour peaking period, catering to peak demand efficiently.

For a low head plant, which turbine is used?
a) Pelton Turbine
b) Francis Turbine
c) Kaplan Turbine
d) All of these

Answer: c
Explanation: Kaplan turbines are specifically designed for low head, high flow conditions, making them the ideal choice for low head hydropower plants.

For a very high head plant, which turbine is used?
a) Pelton Turbine
b) Francis Turbine
c) Kaplan Turbine
d) All of these

Answer: a
Explanation: Pelton turbines are best suited for very high head conditions as their design efficiently converts the energy of high-pressure water jets.

For a medium head plant, which turbine is used?
a) Pelton Turbine
b) Francis Turbine
c) Kaplan Turbine
d) All of these

Answer: b
Explanation: Francis turbines are typically employed in medium head applications because they provide an excellent balance between efficiency and versatility.

To develop a hydropower project, approval is required from:
a) 7 Ministries and 23 Departments
b) 5 Ministries and 13 Departments
c) 1 Ministry and 23 Departments
d) 7 Ministries and 13 Departments

Answer: a) 7 Ministries and 23 Departments
Explanation: Developing a hydropower project involves obtaining clearances from multiple regulatory bodies across several government ministries and departments. In this context, the project typically requires approval from 7 Ministries and 23 Departments in order to ensure adherence to all regulatory, environmental, and technical standards.

The cheapest plant in operation and maintenance is.......
A) Steam power plant
B) Nuclear power plant
C) Hydro-electric power plant
D) None of the above

Answer: C. Hydro-electric power plant
Explanation: Hydro-electric power plants typically have lower operating and maintenance costs when compared to nuclear or steam power plants.

The annual depreciation of a hydro power plant is about........
A) 0.5% to 1.5%
B) 10% to 15%
C) 15% to 20%
D) 20% to 25%

Answer: A. 0.5% to 1.5%
Explanation: Thanks to durable construction and lower wear factors, hydro power plants generally depreciate at a rate of about 0.5% to 1.5% per annum.

The power output from a hydro-electric power plant depends on three parameters.......
A) Head, type and dam of discharge
B) Head, discharge and efficiency of the system
C) Efficiency of the system, type of draft tube and type of turbine used
D) Type of dam, discharge and type of catchment area

Answer: B. Head, discharge and efficiency of the system
Explanation: The output is determined by the water head (vertical drop), the discharge (flow rate) and how efficiently the system converts water energy into electrical power.

Location of the surge tank in a hydro-electric station is near to the.......
A) Tailrace
B) Turbine
C) Reservoir
D) None of the above

Answer: B. Reservoir
Explanation: the surge tank is positioned near the reservoir area to help regulate pressure fluctuations in the system.

Which of the following is the correct equation for the electrical power generated by the hydroelectric power plant?
a) 75×0.736 wQHη Watt
b) (7.5/0.736) × wQHη Watt
c) 0.845 ×wQHη Watt
d) 9.81 ×wQHη

Answer: c
Explanation: Rating of any power plant is expressed by its maximum output power. These are large quantities so rating is given in mega watts.The electrical power generated by this plant is proportional to specific weight of water(w), water head(H), generation efficiency(η), flow rate of water(Q) and acceleration due to gravity.

Which of the following is not a requirement for site selection of hydroelectric power plant?
a) Availability of water
b) Large catchment area
c) Rocky land
d) Sedimentation

Answer: d
Explanation: Sedimentation may reduce the water storage capacity of reservoir and may also cause damage to the turbine blades. Availability of water, large catchment area and rocky land are primary requirements for site selection of hydroelectric power plant.

The amount of electrical energy that can be generated by a hydroelectric power plant depends upon ___________
a) Head of water
b) Quantity of water
c) Specific weight of water
d) Efficiency of Alternator

Answer: b
Explanation: Potential energy of large quantity of stored water is used by hydroelectric power plant to generate electrical energy. Head of water is important to get kinetic energy from that potential energy. Efficiency of alternator represents that what percentage of input mechanical power it can convert into electrical power.

Hydroelectric power plant is __________
a) Non-renewable source of energy
b) Conventional source of energy
c) Non-conventional source of energy
d) Continuous source of energy

Answer: b
Explanation: Hydroelectric power plants are conventional source of energy. About 16.6% of total electricity and about 70% of total renewable energy of world is provided by hydroelectric power plants. They are not Non-renewable because water is inexhaustible. It is not continuous source of energy because its output fluctuates with change in flow rate of water with season.

Hydroelectric power plant is mainly located in ____________
a) Flat areas
b) Deserts
c) Hilly areas
d) Deltas

Answer: c
Explanation: In order to get sufficient head, hydroelectric power plants are constructed in hilly areas. In desert and flat areas sufficient water head cannot be obtained. Deltas are not suitable for this because of high sedimentation.

Which statement about hydroelectric power plant is wrong?
a) Efficiency of hydroelectric power plant does not reduce with age
b) Its construction coast is very high and takes a long time for erection.
c) It is very neat and clean plant because no smoke or ash is produced.
d) Meeting rapidly changing load demands is not possible in hydroelectric power plant.

Answer: d
Explanation: Fluctuating load demands can be met just by controlling the flow of water using valves and gates. Due to its robust construction, its efficiency does not fall with time. Statement ‘b’ is correct because construction of dam, installation of alternator and turbines are very costly.

Which of the following is not an advantage of hydroelectric power plant?
a) no fuel requirement
b) low running cost
c) continuous power source
d) no standby losses

Answer: c
Explanation: Output of such plants is never constant. This is because of their dependency over flow rate of water in river which is seasonal. No fuel requirement low running cost and no standby losses are advantages of hydroelectric power plants.

Which of the following statement is true about hydroelectric power plant?
a) Hydroelectric power plants are multipurpose.
b) Due to non-uniform flow of water frequency control in such plants is very difficult.
c) Hydroelectric power plant has high running cost
d) Water is used as fuel in hydroelectric power plant

Answer: a
Explanation: It is because in addition to generation of electricity they are also used for irrigation, flood control etc. Frequency control in such plants is done easily just by controlling flow of water to the turbine through valves and gates. Due to low maintenance cost and no fuel requirement running cost of a plant is very low. Water is not fuel.

The minimum power which a hydropower plant can generate throughout the year is called as ________________
a) power plant capacity
b) power plant load
c) firm power
d) water power

Answer: c
Explanation: The firm power is the net amount of power which is continuously available from a plant without any break on a guaranteed basis. The consumers can always be sure of getting this power and this power is available under the most adverse hydraulic conditions.

If the peak load for a power plant equals the plant capacity then the ratio of the capacity factor to load factor will be _________________
a) 1
b) 0
c) < 1
d) > 1

Answer: a
Explanation: Load factor = Average load over a certain period / Peak load during that period
Capacity factor = Average load over a given time period / Plant capacity
Since, Plant capacity = Peak load
Ratio of CF / LF = 1.

If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week and the energy produced is 58, 80,000 kWh, the capacity factor for the plant for the week will be ___________________
a) 35%
b) 50%
c) 70%
d) 65%

Answer: a
Explanation: Capacity factor = Average load/ Plant capacity
Average load = Energy produced / Time (in hours) = 58,80,000 / 7 x 24 = 35000 kW
C.F = 35 MW / 100 MW = 0.35 (or 35%).

During a certain week a power plant turns out 84,00,000 kWh and the peak load during the week is 100,000 kW. What is the load factor during the week?
a) 40%
b) 45%
c) 50%
d) 60%

Answer: c
Explanation: Load factor can be defined as the ratio of average load to the peak load over a given period.
Average load = 84,000,000 / (24 x 7) = 50,000 kW
L.F = Average load / Peak load = 50,000 / 100,000 = 0.5 or 50%.

A canal drop is 6 meters and discharges available through the turbine is 50 cumec. Find the electrical energy available.
a) 2352 KW
b) 2352 MW
c) 2.352 kW
d) 235.2 kW

Answer: a
Explanation: The electrical energy (in kW) = 7.84 Q H (using 80% efficiency) where H is the design head in meters and Q is the design discharge in cumecs.
Electrical energy = 7.84 x 50 x 6 = 2352 kW.

The ratio of maximum power utilised to the maximum power available is _____________
a) power factor
b) plant use factor
c) reserve capacity
d) capacity factor

Answer: b
Explanation: Plant use factor is nothing but utilization factor which can be defined as the ratio of maximum power utilized to the maximum power available if the water head is assumed to be constant. The value usually varies from 0.4 to 0.9 for a hydel plant.

The net amount of power which is continuously available from a plant without any break is known as _____________
a) firm power
b) secondary power
c) power factor
d) utilization factor

Answer: a
Explanation: Secondary power is the excess power available over firm power during peak-off hours. It is supplied to consumers as and when available basis. Power factor is the ratio of actual power (in kW) to the apparent power (in kilo volt-ampere).

The value of power factor is generally _____________________
a) equal to unity
b) less than unity
c) greater than unity
d) equal to zero

Answer: b
Explanation: The value of power factor depends upon the relationship between the inductance and resistance in the load and it can never be greater than unity. The usual system load has a power factor varying from 0.8 to 0.9. But if various induction motors are installed in the load, the value will be 0.5.

To ensure maximum overall plant efficiency, the rated head should be equal to ______________
a) the design head
b) the gross head
c) the operating head
d) effective head

Answer: a
Explanation: The Rated head is the head at which the turbine functioning at full gate opening will produce a power output. It is nothing but the specified head that is in the nameplate of the turbine. This is equal to the design head of the turbine so as to ensure maximum overall plant efficiency.

The difference of head at the point of entry and exit of turbine is _______________
a) design head
b) gross head
c) effective head
d) rated head

Answer: c
Explanation: Design head is the net head under which the turbine reaches peak efficiency. The difference in the water level elevations at the point of diversion of water for the hydel scheme and the point of return of water back to the river is called a gross head. The rated head is the head that is specified in the name-plate of the turbine.

The load on a hydel plant varies from a minimum of 10,000 kW to a maximum of 35,000 kW. Two turbo-generators of capacities 20,000 kW each have been installed. Calculate Plant factor.
a) 50%
b) 51%
c) 56.2%
d) 59.7%

Answer: c
Explanation: Plant factor can be defined as the ratio of the energy actually produced (Average load) to the maximum energy that can be produced at a particular time.
Since two turbo generators are installed, the total installed capacity = 40000 kW
P.F = [(10000 + 35000) / 2] / 40000 = 56%.

Calculate utilisation factor if the maximum power utilised is 40,000 kW and two turbo generators installed each of capacity 23,000 kW.
a) 73%
b) 87%
c) 57.5%
d) 63%

Answer: b
Explanation: Utilisation factor = Maximum power utilised / Maximum power available
U.F = 40,000 / (2 x 23000) = 86.9% (since two generators are installed).

If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week. Calculate the utilization factor.
a) 0.35
b) 0.50
c) 0.70
d) 0.60

Answer: c
Explanation: The utilization factor is the ratio of the maximum power utilized to the maximum power available.
U.F = Max power utilised/ Max power available = 70 / 100 = 0.7.

400 cumecs of water are being released from dam storage to meet the downstream demand through the turbines of the connected hydro plant. The effective head of water acting on the turbines is 50 m. The efficiency of the hydro plant is 0.8. The electrical power generated from this plant is __________________
a) 1,56,800 MW
b) 156.8 M kW
c) 156.8 MW
d) 156.8 kW

Answer: c
Explanation: Using 80% efficiency, Electrical energy = 7.84 QH where H is the design head in meters and Q is the design discharge in cumecs.
Electrical energy = 7.84 x 400 x 50 = 1, 56,800 kW = 156.80 MW.

What is the highest elevation of water level that can be maintained in the reservoir without any spillway discharge either with gated or non-gated spillway?
a) Normal Water level
b) Minimum Water level
c) Weighted average level
d) Operating head

Answer: a
Explanation: Minimum water level is that elevation of water level which produces minimum net head on the power units i.e. 65% of the design head. The weighted average level is the level above and below which equal amounts of power are developed during an average year. Operating head is the difference of elevation of entrance and the tail-race exit.

The minimum power which a hydropower plant can generate throughout the year is called as ________________
a) power plant capacity
b) power plant load
c) firm power
d) water power

Answer: c
Explanation: The firm power is the net amount of power which is continuously available from a plant without any break on a guaranteed basis. The consumers can always be sure of getting this power and this power is available under the most adverse hydraulic conditions.

If the peak load for a power plant equals the plant capacity then the ratio of the capacity factor to load factor will be _________________
a) 1
b) 0
c) < 1
d) > 1

Answer: a
Explanation: Load factor = Average load over a certain period / Peak load during that period
Capacity factor = Average load over a given time period / Plant capacity
Since, Plant capacity = Peak load
Ratio of CF / LF = 1.

If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week and the energy produced is 58, 80,000 kWh, the capacity factor for the plant for the week will be ___________________
a) 35%
b) 50%
c) 70%
d) 65%

Answer: a
Explanation: Capacity factor = Average load/ Plant capacity
Average load = Energy produced / Time (in hours) = 58,80,000 / 7 x 24 = 35000 kW
C.F = 35 MW / 100 MW = 0.35 (or 35%).

During a certain week a power plant turns out 84,00,000 kWh and the peak load during the week is 100,000 kW. What is the load factor during the week?
a) 40%
b) 45%
c) 50%
d) 60%

Answer: c
Explanation: Load factor can be defined as the ratio of average load to the peak load over a given period.
Average load = 84,000,000 / (24 x 7) = 50,000 kW
L.F = Average load / Peak load = 50,000 / 100,000 = 0.5 or 50%.

A canal drop is 6 meters and discharges available through the turbine is 50 cumec. Find the electrical energy available.
a) 2352 KW
b) 2352 MW
c) 2.352 kW
d) 235.2 kW

Answer: a
Explanation: The electrical energy (in kW) = 7.84 Q H (using 80% efficiency) where H is the design head in meters and Q is the design discharge in cumecs.
Electrical energy = 7.84 x 50 x 6 = 2352 kW.

The ratio of maximum power utilised to the maximum power available is _____________
a) power factor
b) plant use factor
c) reserve capacity
d) capacity factor

Answer: b
Explanation: Plant use factor is nothing but utilization factor which can be defined as the ratio of maximum power utilized to the maximum power available if the water head is assumed to be constant. The value usually varies from 0.4 to 0.9 for a hydel plant.

The net amount of power which is continuously available from a plant without any break is known as _____________
a) firm power
b) secondary power
c) power factor
d) utilization factor

Answer: a
Explanation: Secondary power is the excess power available over firm power during peak-off hours. It is supplied to consumers as and when available basis. Power factor is the ratio of actual power (in kW) to the apparent power (in kilo volt-ampere).

The value of power factor is generally _____________________
a) equal to unity
b) less than unity
c) greater than unity
d) equal to zero

Answer: b
Explanation: The value of power factor depends upon the relationship between the inductance and resistance in the load and it can never be greater than unity. The usual system load has a power factor varying from 0.8 to 0.9. But if various induction motors are installed in the load, the value will be 0.5.

To ensure maximum overall plant efficiency, the rated head should be equal to ______________
a) the design head
b) the gross head
c) the operating head
d) effective head

Answer: a
Explanation: The Rated head is the head at which the turbine functioning at full gate opening will produce a power output. It is nothing but the specified head that is in the nameplate of the turbine. This is equal to the design head of the turbine so as to ensure maximum overall plant efficiency.

The difference of head at the point of entry and exit of turbine is _______________
a) design head
b) gross head
c) effective head
d) rated head

Answer: c
Explanation: Design head is the net head under which the turbine reaches peak efficiency. The difference in the water level elevations at the point of diversion of water for the hydel scheme and the point of return of water back to the river is called a gross head. The rated head is the head that is specified in the name-plate of the turbine.

The load on a hydel plant varies from a minimum of 10,000 kW to a maximum of 35,000 kW. Two turbo-generators of capacities 20,000 kW each have been installed. Calculate Plant factor.
a) 50%
b) 51%
c) 56.2%
d) 59.7%

Answer: c
Explanation: Plant factor can be defined as the ratio of the energy actually produced (Average load) to the maximum energy that can be produced at a particular time.
Since two turbo generators are installed, the total installed capacity = 40000 kW
P.F = [(10000 + 35000) / 2] / 40000 = 56%.

Calculate utilisation factor if the maximum power utilised is 40,000 kW and two turbo generators installed each of capacity 23,000 kW.
a) 73%
b) 87%
c) 57.5%
d) 63%

Answer: b
Explanation: Utilisation factor = Maximum power utilised / Maximum power available
U.F = 40,000 / (2 x 23000) = 86.9% (since two generators are installed).

If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week. Calculate the utilization factor.
a) 0.35
b) 0.50
c) 0.70
d) 0.60

Answer: c
Explanation: The utilization factor is the ratio of the maximum power utilized to the maximum power available.
U.F = Max power utilised/ Max power available = 70 / 100 = 0.7.

400 cumecs of water are being released from dam storage to meet the downstream demand through the turbines of the connected hydro plant. The effective head of water acting on the turbines is 50 m. The efficiency of the hydro plant is 0.8. The electrical power generated from this plant is __________________
a) 1,56,800 MW
b) 156.8 M kW
c) 156.8 MW
d) 156.8 kW

Answer: c
Explanation: Using 80% efficiency, Electrical energy = 7.84 QH where H is the design head in meters and Q is the design discharge in cumecs.
Electrical energy = 7.84 x 400 x 50 = 1, 56,800 kW = 156.80 MW.

What is the highest elevation of water level that can be maintained in the reservoir without any spillway discharge either with gated or non-gated spillway?
a) Normal Water level
b) Minimum Water level
c) Weighted average level
d) Operating head

Answer: a
Explanation: Minimum water level is that elevation of water level which produces minimum net head on the power units i.e. 65% of the design head. The weighted average level is the level above and below which equal amounts of power are developed during an average year. Operating head is the difference of elevation of entrance and the tail-race exit.

What is the primary function of a Diversion Structure in a hydropower project?
a) To filter out fine sediments from the water
b) To divert water from the natural river course to the intake
c) To store water for later use
d) To provide a reserve of water for augmented flow

Answer: b
Explanation: The primary function of the Diversion Structure is to redirect water from the river or stream into the intake of the hydropower project.

What is the role of the Intake in a hydropower plant?
a) To discharge water back to the river
b) To regulate water flow and prevent debris from entering the penstock
c) To store water for flood control
d) To convert water energy into electricity

Answer: b
Explanation: The Intake collects water from the diversion structure, regulates the flow, and prevents debris from entering the penstock.

What is the primary function of a Gravel Trap in a hydropower scheme?
a) To filter fine silt particles
b) To boost the water pressure
c) To remove gravel and other debris upstream of the intake
d) To store water during peak flow periods

Answer: c
Explanation: The Gravel Trap removes gravel and debris before the water reaches the intake, protecting downstream components from damage.

What is the primary purpose of a Settling Basin in hydropower design?
a) To increase the water velocity
b) To allow sediment and heavy particles to settle by slowing down water velocity
c) To redirect water into the penstock
d) To remove debris using high-pressure jets

Answer: b
Explanation: The Settling Basin slows down the water to allow sediment and heavy particles to settle at the bottom, removing solids before water reaches the powerhouse.

What is the main function of the Headrace Conveyance system?
a) To store water temporarily
b) To filter debris from the water
c) To transport water from the intake to the fore bay
d) To regulate the water pressure upstream of the turbine

Answer: c
Explanation: The Headrace Conveyance transports water from the intake (and settling basin) to the fore bay.

What is the primary function of the Fore Bay in a hydropower plant?
a) To provide a reservoir for water storage and regulate flow to the powerhouse
b) To filter out sediments from the water
c) To act as the main electricity generation unit
d) To increase the water velocity prior to the surge tank

Answer: a
Explanation: The Fore Bay acts as a small reservoir that holds water to regulate flow and maintain a constant head for the turbines.

What is the purpose of a Surge Tank/Head Tank in a hydropower system?
a) To store large quantities of water for emergency use
b) To absorb pressure fluctuations (water hammer) in the penstock
c) To directly drive the turbine
d) To filter out debris from the water

Answer: b
Explanation: The Surge Tank or Head Tank absorbs sudden pressure fluctuations in the penstock, protecting the system from water hammer.

What is the primary role of the Penstock in a hydropower plant?
a) To discharge water back into the river
b) To convey water with high pressure and velocity from the fore bay to the turbines
c) To filter sediment from the water
d) To regulate water flow into the intake

Answer: b
Explanation: The Penstock is a large pipe that delivers high-pressure water from the fore bay to the turbines.

What is the function of Anchor Blocks/Support Piers in a hydropower project?
a) To support and stabilize the penstock
b) To regulate water flow into the turbine
c) To store water during low-flow periods
d) To act as the primary electricity conversion unit

Answer: a
Explanation: Anchor Blocks or Support Piers provide critical support and stability to the penstock, preventing movement due to external forces.

Which statement best describes the primary function of the Powerhouse?
a) It diverts water from the river
b) It houses the turbines and generators to convert water energy into electricity
c) It stores water for flood control
d) It filters sediment and debris before the water reaches the turbines

Answer: b
Explanation: The Powerhouse is where the turbines, generators, and electrical equipment are housed to convert the energy of flowing water into electricity.

What is the primary purpose of a Tailrace in a hydropower plant?
a) To increase the water head before it enters the turbine
b) To channel the discharged water back into the river while maintaining ecological balance
c) To divert water from the intake
d) To regulate the water flow into the intake structure

Answer: b
Explanation: The Tailrace returns water from the powerhouse back to the river or downstream channel, ensuring ecological balance and minimizing erosion.

What is the primary function of a Diversion Structure in a hydropower project?
a) To filter out fine sediments from the water
b) To divert water from the natural river course to the intake
c) To store water for later use
d) To provide a reserve of water for augmented flow

Answer: b
Explanation: The primary function of the Diversion Structure is to redirect water from the river or stream into the intake of the hydropower project.

What is the role of the Intake in a hydropower plant?
a) To discharge water back to the river
b) To regulate water flow and prevent debris from entering the penstock
c) To store water for flood control
d) To convert water energy into electricity

Answer: b
Explanation: The Intake collects water from the diversion structure, regulates the flow, and prevents debris from entering the penstock.

What is the primary function of a Gravel Trap in a hydropower scheme?
a) To filter fine silt particles
b) To boost the water pressure
c) To remove gravel and other debris upstream of the intake
d) To store water during peak flow periods

Answer: c
Explanation: The Gravel Trap removes gravel and debris before the water reaches the intake, protecting downstream components from damage.

What is the primary purpose of a Settling Basin in hydropower design?
a) To increase the water velocity
b) To allow sediment and heavy particles to settle by slowing down water velocity
c) To redirect water into the penstock
d) To remove debris using high-pressure jets

Answer: b
Explanation: The Settling Basin slows down the water to allow sediment and heavy particles to settle at the bottom, removing solids before water reaches the powerhouse.

What is the main function of the Headrace Conveyance system?
a) To store water temporarily
b) To filter debris from the water
c) To transport water from the intake to the fore bay
d) To regulate the water pressure upstream of the turbine

Answer: c
Explanation: The Headrace Conveyance transports water from the intake (and settling basin) to the fore bay.

What is the primary function of the Fore Bay in a hydropower plant?
a) To provide a reservoir for water storage and regulate flow to the powerhouse
b) To filter out sediments from the water
c) To act as the main electricity generation unit
d) To increase the water velocity prior to the surge tank

Answer: a
Explanation: The Fore Bay acts as a small reservoir that holds water to regulate flow and maintain a constant head for the turbines.

What is the purpose of a Surge Tank/Head Tank in a hydropower system?
a) To store large quantities of water for emergency use
b) To absorb pressure fluctuations (water hammer) in the penstock
c) To directly drive the turbine
d) To filter out debris from the water

Answer: b
Explanation: The Surge Tank or Head Tank absorbs sudden pressure fluctuations in the penstock, protecting the system from water hammer.

What is the primary role of the Penstock in a hydropower plant?
a) To discharge water back into the river
b) To convey water with high pressure and velocity from the fore bay to the turbines
c) To filter sediment from the water
d) To regulate water flow into the intake

Answer: b
Explanation: The Penstock is a large pipe that delivers high-pressure water from the fore bay to the turbines.

What is the function of Anchor Blocks/Support Piers in a hydropower project?
a) To support and stabilize the penstock
b) To regulate water flow into the turbine
c) To store water during low-flow periods
d) To act as the primary electricity conversion unit

Answer: a
Explanation: Anchor Blocks or Support Piers provide critical support and stability to the penstock, preventing movement due to external forces.

Which statement best describes the primary function of the Powerhouse?
a) It diverts water from the river
b) It houses the turbines and generators to convert water energy into electricity
c) It stores water for flood control
d) It filters sediment and debris before the water reaches the turbines

Answer: b
Explanation: The Powerhouse is where the turbines, generators, and electrical equipment are housed to convert the energy of flowing water into electricity.

What is the primary purpose of a Tailrace in a hydropower plant?
a) To increase the water head before it enters the turbine
b) To channel the discharged water back into the river while maintaining ecological balance
c) To divert water from the intake
d) To regulate the water flow into the intake structure

Answer: b
Explanation: The Tailrace returns water from the powerhouse back to the river or downstream channel, ensuring ecological balance and minimizing erosion.

Which component of a dam is designed to allow the passage of surplus water from the reservoir?
a) Penstock
b) Spillway
c) Abutments
d) Gallery

Answer: b
Explanation: The spillway is the structure built near the top of the dam to safely pass excess water from the reservoir.

The valley slopes on either side of a dam, to which its ends are fixed, are known as:
a) Gallery
b) Abutments
c) Free Board
d) Diversion Tunnel

Answer: b
Explanation: Abutments are the natural valley slopes that support the lateral ends of the dam structure.

Which dam component is a level or gently sloping tunnel-like passage used to accommodate drainage and instrumentation?
a) Sluiceway
b) Gallery
c) Surge Tank
d) Draft Tube

Answer: b
Explanation: A gallery is an internal passage in the dam used for seepage drainage, drilling holes for grout, and housing instrumentation.

What is the primary function of a sluiceway in dam design?
a) To store water
b) To clear silt accumulation in the reservoir
c) To divert water for hydropower
d) To support the dam’s structure

Answer: b
Explanation: The sluiceway is an opening near the base of the dam that enables the flushing out of accumulated silt from the reservoir.

In dam terminology, what does “free board” refer to?
a) The dam’s overall height
b) The vertical distance between the maximum water level in the reservoir and the top of the dam
c) The width of the dam at its base
d) The depth of the reservoir below the dam

Answer: b
Explanation: Free board is the space between the highest water elevation in the reservoir and the top of the dam, ensuring safety against overtopping.

Which term describes the minimum storage level in a reservoir below which water is not withdrawn?
a) Free Board
b) Dead Storage Level
c) Spillway Level
d) Active Storage Level

Answer: b
Explanation: The dead storage level is the permanent storage zone in a reservoir that is not used for withdrawing water.

What is the main purpose of a diversion tunnel in dam construction?
a) To provide an alternative water route during construction
b) To generate hydropower
c) To store flood water permanently
d) To drain seepage water from the dam body

Answer: a
Explanation: A diversion tunnel is constructed to divert river water away from the dam construction site, allowing work to proceed safely and efficiently.

Which dam type is primarily constructed to store excess water for multiple uses such as irrigation, water supply, and hydroelectric power generation?
a) Diversion Dam
b) Detention Dam
c) Storage Dam
d) Check Dam

Answer: c
Explanation: Storage dams are built specifically to store flood water, which can then be utilized for various purposes including agriculture and power generation.

Which dam is constructed mainly to divert river water into canals or conduits?
a) Storage Dam
b) Diversion Dam
c) Detention Dam
d) Coffer Dam

Answer: b
Explanation: Diversion dams are primarily designed to raise the water level to a certain height so that it can be diverted into canals for irrigation or other uses.

Under hydraulic design classification, which dam allows the overflow of surplus water above its structure?
a) Non-Overflow Dam
b) Overflow Dam
c) Arch Dam
d) Gravity Dam

Answer: b
Explanation: An overflow dam includes a section that allows excess (surplus) water to flow over the dam safely.

Which type of dam resists water pressure primarily by using its own weight?
a) Arch Dam
b) Buttress Dam
c) Gravity Dam
d) Embankment Dam

Answer: c
Explanation: Gravity dams rely on their massive weight to counteract the force of the water pushing against them.

Which dam is characterized by its curved shape with the convex side facing upstream to effectively transfer water pressure to the abutments?
a) Arch Dam
b) Buttress Dam
c) Gravity Dam
d) Embankment Dam

Answer: a
Explanation: Arch dams use the arch action to transfer the load of the water to the valley walls (abutments), making them efficient in narrow, rocky sites.

Which dam structure features an upstream sloping deck supported by a series of reinforced concrete buttresses or piers?
a) Arch Dam
b) Buttress Dam
c) Gravity Dam
d) Embankment Dam

Answer: b
Explanation: Buttress dams use a sloping upstream face that is supported by buttresses, which help transmit the water pressure to the foundation.

Embankment dams are typically constructed using which of the following materials?
a) Concrete and steel
b) Locally available soils, gravel, and sand
c) Reinforced polymers
d) Prefabricated metal panels

Answer: b
Explanation: Embankment dams are built from locally available natural materials, which rely on their shear strength to resist water pressure.

Which of the following is NOT a typical component found in a hydropower station or storage plant?
a) Surge Tank
b) Turbine
c) Draft Tube
d) Waterwheel

Answer: d
Explanation: While surge tanks, turbines, and draft tubes are common components of hydropower installations, waterwheels are not typically used in modern hydropower plants.

In a hydropower plant, what is the primary function of a surge tank?
a) Increase water speed
b) Regulate water pressure transients
c) Generate additional electricity
d) Provide structural reinforcement

Answer: b
Explanation: The surge tank absorbs sudden pressure surges, reducing water hammer effects and ensuring smooth flow conditions in the water conduit.

Which dam is primarily constructed for soil conservation by trapping debris such as sand, gravel, and driftwood?
a) Check (Debris) Dam
b) Storage Dam
c) Diversion Dam
d) Coffer Dam

Answer: a
Explanation: A check or debris dam is designed to slow down flow and accumulate debris, which helps in soil conservation and prevents downstream sedimentation.

Which dam component provides a passage used for drilling grout holes and installing monitoring instrumentation?
a) Diversion Tunnel
b) Gallery
c) Abutments
d) Sluiceway

Answer: b
Explanation: The gallery is an internal, gently sloping passage within the dam used for both drainage and housing instrumentation to monitor the dam’s performance.

What is the main advantage of an arch dam compared to a gravity dam?
a) Greater storage capacity
b) Reduced material requirements due to arch action
c) Better silt management
d) Ease of construction in all terrains

Answer: b
Explanation: Arch dams use their curved design to transfer water pressure efficiently to the abutments, allowing reduced concrete volume compared to a massive gravity dam.

Which classification of dam is based on the construction method and materials used?
a) Function and Use Classification
b) Hydraulic Design Classification
c) Structural Design Classification
d) Environmental Impact Classification

Answer: c
Explanation: Structural design classification categorizes dams based on their construction method and materials—for example, gravity, arch, buttress, and embankment dams.

Under the function and use classification, which dam is built primarily to store water for irrigation, water supply, and power generation?
a) Diversion Dam
b) Storage Dam
c) Detention Dam
d) Check Dam

Answer: b
Explanation: Storage dams are designed for long-term water storage that can later be used for multiple purposes such as irrigation, domestic supply, and hydropower generation.

In a hydropower plant, which component converts the mechanical energy of water into electrical energy?
a) Turbine
b) Generator
c) Draft Tube
d) Surge Tank

Answer: b
Explanation: While the turbine converts water energy into mechanical energy, the generator goes one step further by transforming that mechanical energy into electrical energy.

Which type of dam is best suited for a deep, narrow valley where the forces can be efficiently transmitted to the side walls?
a) Embankment Dam
b) Gravity Dam
c) Arch Dam
d) Buttress Dam

Answer: c
Explanation: Arch dams are preferred in narrow, rocky locations where their curved shape efficiently transfers water pressure to the abutments.

What is the role of a coffer dam during dam construction?
a) To permanently divert water
b) To temporarily isolate the construction area from river water
c) To store water for later use
d) To generate hydroelectric power

Answer: b
Explanation: A coffer dam is constructed temporarily to block water flow, isolating the construction area from the river during the dam’s construction.

Which dam component commonly houses instruments for monitoring seepage and dam stability?
a) Abutments
b) Gallery
c) Sluiceway
d) Free Board

Answer: b
Explanation: The gallery provides access for installing various monitoring instruments and also facilitates the drainage of seepage water.

Which of the following is NOT one of the typical purposes of a dam as mentioned in the text?
a) Flood Mitigation
b) Recreation
c) Industrial Waste Management
d) Navigation

Answer: c
Explanation: While dams serve many purposes such as flood control, recreation, and navigation, industrial waste management is not one of the listed purposes.

What design feature allows a gravity dam to effectively resist the pressure of the water?
a) Its curved shape
b) Its massive weight
c) Its specialized drainage system
d) Its flexible structure

Answer: b
Explanation: Gravity dams rely on their heavy mass to counteract the force of the water pressing against them.

Under hydraulic design classification, a dam that prevents water from overtopping its crest is known as a?
a) Overflow Dam
b) Non-Overflow Dam
c) Arch Dam
d) Check Dam

Answer: b
Explanation: In a non-overflow dam, the design ensures that water does not flow over the top, unlike overflow dams which have a designated spillway section.

Which type of dam is primarily constructed to control rapid floodwaters and protect downstream areas?
a) Storage Dam
b) Detention Dam
c) Diversion Dam
d) Embankment Dam

Answer: b
Explanation: Detention dams are specifically built to manage and control floodwaters, reducing the risk of downstream flooding.

Which dam classification considers the dam’s ability to safely allow excess water to flow over its top?
a) Overflow Dam
b) Non-Overflow Dam
c) Gravity Dam
d) Check Dam

Answer: a
Explanation: An overflow dam is designed with a spillway or crest section that permits surplus water to safely flow over the structure.

According to the classification as per height, a dam with a height of 120 m should be classified as:
a) Low Dam
b) Medium Dam
c) High Dam or Large Dam
d) None of the above

Answer: c
Explanation: A dam taller than 100 m qualifies as a High Dam or Large Dam.

What is the height range for a dam classified as a Medium Dam?
a) Less than 50 m
b) Between 50 m and 100 m
c) Greater than 100 m
d) 30 m to 70 m

Answer: b
Explanation: Medium Dams are defined as having heights between 50 m and 100 m.

Which classification of dam distinguishes between dam types based on construction materials?
a) Classification as per Height
b) Classification as per Material of Construction
c) Classification as per Site Selection
d) Classification as per Function

Answer: b
Explanation: The classification as per material of construction differentiates between Rigid Dams (made of concrete or masonry) and Non-Rigid Dams (made of materials like earth or rock fill).

Which of the following is NOT included as a factor in the selection of a dam site?
a) Foundation
b) Topography
c) Construction Material
d) Aesthetic Color

Answer: d
Explanation: Factors such as foundation, topography, reservoir, catchment area, spillway, construction material, communication, and environmental conditions are considered. Aesthetic color is not a standard site selection factor.

In stability analysis, the factor of safety against overturning for a dam should generally be greater than:
a) 1.0
b) 1.5
c) 2.0
d) 2.5

Answer: b
Explanation: A factor of safety greater than 1.5 is generally required to prevent overturning of the dam.

The vertical stress distribution at the base of a dam is given by the equation:
p = Direct Stress + _______
a) Lateral Stress
b) Uplift Pressure
c) Bending Stress
d) Frictional Stress

Answer: c
Explanation: The equation for vertical stress at the base is p = Direct Stress + Bending Stress.

Sliding (or shear failure) in a dam occurs when:
a) The vertical forces are excessive
b) The net horizontal force exceeds the frictional resistance
c) The overturning moments are balanced
d) The dam material experiences too much compression

Answer: b
Explanation: Sliding occurs when the external horizontal forces exceed the frictional resistance between the dam and its foundation.

Which foundation treatment method involves drilling shallow holes to inject a grout mixture at low pressure?
a) Curtain Grouting
b) Consolidation Grouting
c) Surface Stepping
d) Shear Key Installation

Answer: b
Explanation: Consolidation grouting involves drilling shallow holes (B holes) and injecting a cement-water grout at low pressure (30–40 N/cm²) to consolidate the foundation.

Why is the foundation surface stepped during dam construction?
a) To reduce concrete usage
b) To increase frictional resistance against sliding
c) To simplify the layout
d) To accommodate drainage pipes

Answer: b
Explanation: Stepping the foundation surface increases its frictional resistance, helping to prevent sliding of the dam.

Curtain grouting is performed primarily to:
a) Prevent tension cracks
b) Provide a waterproof barrier against leakage
c) Increase the dam’s height
d) Enhance compressive strength

Answer: b
Explanation: Curtain grouting is used after initial concreting to form a barrier that prevents leakage through the dam’s foundation.

Which factor is most critical when selecting the type of dam?
a) Geology of foundation and river bank
b) Local cultural preferences
c) Aesthetic appeal
d) Proximity to urban areas

Answer: a
Explanation: A sound geological foundation, including the river bank characteristics, is fundamental for dam design.

Which topographic feature is most favorable for the construction of a dam?
a) V-shaped narrow gorge
b) Wide, flat plain
c) Urban area
d) Coastal dune area

Answer: a
Explanation: A V-shaped narrow gorge offers natural confinement, making it an ideal site for dam construction.

What does a solid rock foundation with no faults or fissures allow in terms of dam construction?
a) Only earth dams can be constructed
b) Only gravity dams can be built
c) Any type of dam can be constructed
d) Only arch dams are feasible

Answer: c
Explanation: When the foundation is solid rock without faults, engineers can choose from any dam type.

Which rock types provide a good foundation for the construction of a gravity dam?
a) Granite, gneiss, and schist
b) Sandstone and shale
c) Limestone and dolomite
d) Siltstone and claystone

Answer: a
Explanation: Granite, gneiss, and schist are strong, stable rocks that make excellent foundations for gravity dams.

If the foundation is composed of silt and fine sand, which type of dam is most appropriate?
a) Arch dam
b) Earthen dam or low concrete gravity dam
c) Rock fill dam
d) Overflow concrete dam

Answer: b
Explanation: Silt and fine sand foundations are prone to seepage and settlement, so earthen dams or low concrete gravity dams are preferred.

When a separate site for the spillway is available, which dam type may be preferred?
a) Arch dam
b) Earthen dam
c) Gravity dam with overflow spillway
d) Rock fill dam

Answer: b
Explanation: Having a separate spillway site can favor the selection of an earthen dam.

What is the primary purpose of incorporating a spillway in a dam design?
a) To dissipate water energy
b) To safely dispose of flood water
c) To support the dam structure
d) To supply water for irrigation

Answer: b
Explanation: The spillway is essential for safely discharging excess flood water from the reservoir.

Why is a roadway often provided on the top of a dam?
a) For agricultural activities
b) For recreational access
c) For maintenance and operational access
d) For water supply distribution

Answer: c
Explanation: The roadway on the dam crest facilitates maintenance and operational activities.

When vertical acceleration acts downward, what happens to the effective weight of the dam?
a) It increases
b) It decreases
c) It remains unchanged
d) It fluctuates unpredictably

Answer: b
Explanation: Downward acceleration creates an upward inertia force that decreases the effective weight of the dam.

In wave pressure calculations, what does the variable hw represent?
a) Wind velocity
b) Fetch length of the water body
c) Wave height from crest to trough
d) Dam height

Answer: c
Explanation: The variable hw defines the wave height measured from its crest to trough.

According to the design principles, what is the maximum wave pressure intensity in terms of hw?
a) 1.2 × hw
b) 2.4 × hw
c) 3 × hw
d) 0.5 × hw

Answer: b
Explanation: The design specifies that the maximum wave pressure intensity is 2.4 times the wave height (hw).

Which condition is NOT suitable for constructing a gravity dam?
a) Presence of a solid rock foundation
b) Dam height greater than 250 m
c) Adequate base width
d) Limited water pressure

Answer: b
Explanation: Gravity dams are generally unsuitable when the dam height exceeds 250 m.

In assessing the structural stability of a concrete gravity dam, which of the following is not typically considered?
a) Resistance to sliding
b) Resistance to lifting
c) Resistance to overturning
d) Resistance to seepage

Answer: d
Explanation: Structural stability focuses on sliding, lifting, overturning, bearing, and shearing; seepage is managed separately.

Which method is not mentioned as a stability analysis technique for gravity dams?
a) Gravity method
b) Trial load twist method
c) Slab analogy method
d) Finite element method

Answer: d
Explanation: The finite element method is not included in the provided list of stability analysis methods.

Which of the following is a common demerit of earthen dams?
a) High construction cost
b) Risk of damage or destruction due to overtopping
c) Exceptional durability
d) Minimal maintenance requirements

Answer: b
Explanation: Earthen dams are vulnerable to overtopping and internal erosion, leading to potential damage.

What is an effective measure to prevent erosion of the downstream toe in an earthen dam?
a) Increasing spillway capacity
b) Reducing dam height
c) Providing stone pitching or riprap protection
d) Installing vertical reinforcements

Answer: c
Explanation: Stone pitching or riprap is routinely used to protect the downstream toe from erosive forces.

What is the thumb rule for determining the top width (W) of very low earthen dams?
a) W = H/3 + 3
b) W = H/5 + 3
c) W = H/5
d) W = 1.65(H + 1.5)1/3

Answer: b
Explanation: For very low dams, the top width is generally determined by the rule W = H/5 + 3.

How is the free board of a dam generally determined?
a) It is equal to the dam height
b) It is 1.5 times the wave height (hw)
c) It is half of the dam height
d) It is a fixed measurement of 2 m

Answer: b
Explanation: Typically, the free board is set at 1.5 times the wave height (hw) to prevent overtopping.

Which of the following is used to prevent seepage through an earthen dam embankment?
a) Vertical reinforcement
b) Horizontal drainage filter
c) Increasing the dam height
d) Installing additional overflow channels

Answer: b
Explanation: A horizontal drainage filter is an effective technique to control seepage within earthen dams.

Aside from horizontal drainage filters, what is another method used to prevent seepage through an earthen dam?
a) Providing chimney drains
b) Widening the dam
c) Reducing spillway capacity
d) Installing vertical concrete cylinders

Answer: a
Explanation: Chimney drains extend upward into the embankment, enhancing drainage and mitigating seepage.

Which dam type is typically chosen when a large integrated spillway is required?
a) Earthen dam with a separate spillway
b) Overflow concrete gravity dam
c) Arch dam
d) Rock fill dam

Answer: b
Explanation: An overflow concrete gravity dam featuring an integrated spillway is preferred when a large capacity is needed for flood water discharge.

What primarily resists overturning in a gravity dam?
a) Lateral forces
b) The dam’s weight
c) Foundation reinforcement
d) Seepage control measures

Answer: b
Explanation: Overturning is resisted mainly by the enormous weight of the dam, which provides the necessary stability.

When vertical acceleration acts upward, how is the effective weight of the dam affected?
a) It decreases due to upward inertia
b) It increases due to downward inertia
c) It remains the same
d) It becomes negligible

Answer: b
Explanation: Upward acceleration creates a downward inertia force, thereby increasing the dam’s effective weight.

What percentage of the dam height is recommended for establishing filter drainage in an earthen dam?
a) 10–15%
b) 25–30%
c) 50–60%
d) 75–80%

Answer: b
Explanation: Filter drainage is typically designed to be 25–30% of the dam height in order to effectively control seepage.

Why is it important to keep the phreatic (seepage) line within the downstream face of an earthen dam?
a) To reduce construction costs
b) To prevent sloughing or erosion of the dam face
c) To increase reservoir capacity
d) For better aesthetic integration

Answer: b
Explanation: Maintaining the phreatic line within the downstream face helps prevent sloughing or erosion of the dam, ensuring long‐term stability.

What are the two sub-methods of the gravity method for dam stability analysis?
a) Graphical and Numerical methods
b) Graphical and Analytical methods
c) Empirical and Analytical methods
d) Experimental and Graphical methods

Answer: b
Explanation: The gravity method is divided into graphical and analytical methods to assess dam stability.

In dam stability analysis, why are moments taken about the lower middle third of the base?
a) To simplify calculations
b) To accurately locate the resultant force
c) Because that area experiences the highest stress
d) To minimize uplift effects

Answer: b
Explanation: Moments are calculated about the lower middle third to accurately determine the position (and thus the eccentricity) of the resultant force, which is critical for stability analysis.

In a stability analysis against sliding, which force primarily provides the necessary resistance?
a) The lateral hydrostatic pressure
b) Frictional force resulting from the dam's weight
c) Uplift pressure
d) Seismic inertia forces

Answer: b
Explanation: Friction generated by the massive weight of the dam (μ(W – U)) is used to counteract horizontal forces and prevent sliding.

Which environmental parameters directly influence the wave pressure exerted on a dam?
a) Dam crest elevation and spillway design
b) Wind velocity and fetch length
c) Downstream slope gradient and foundation type
d) Seepage measures and roadway design

Answer: b
Explanation: Wind velocity and the fetch length are key factors in determining the wave height (hw), which in turn affects the wave pressure on the dam.

How does geology influence dam design?
a) It only affects the dam’s aesthetic appearance
b) It governs the strength of the foundation and the type of dam that can be safely constructed
c) It is only a minor consideration compared to hydrology
d) It solely determines the availability of construction materials

Answer: b
Explanation: Geology is crucial as it affects the quality of the foundation, controls seepage potential, and influences the choice of the dam type.

Which factor is NOT typically considered a general design consideration for dams?
a) Hydrologic considerations
b) Construction material availability
c) Foundation treatment
d) Local tourism development

Answer: d
Explanation: Local tourism is not a primary factor in dam design compared to essential engineering considerations such as hydrology, material properties, and foundation treatment.

What structural protection measure is typically used on both upstream and downstream slopes in an earthen dam?
a) Installing additional overflow channels
b) Protecting with riprap, berms, or vegetation
c) Increasing the dam’s thickness
d) Reinforcing with steel beams

Answer: b
Explanation: To protect against erosive actions such as rain, waves, and runoff, riprap, berms, or vegetation are typically applied to the slopes of an earthen dam.

Which of the following best describes the primary purpose of curtain grouting in dam construction?
a) To support the dam structure
b) To form a principal barrier against seepage and reduce uplift pressures
c) To enhance the dam’s aesthetic appearance
d) To provide additional reservoir storage

Answer: b
Explanation: Curtain grouting is performed to form a barrier (curtain) that limits seepage through the foundation and reduces uplift pressures.

What is the typical spacing between the drilled holes for high-pressure curtain grouting?
a) 0.5 to 0.8 m
b) 1.2 to 1.5 m
c) 2.0 to 2.5 m
d) 3.0 to 3.5 m

Answer: b
Explanation: The grouting holes are typically spaced between 1.2 and 1.5 m apart.

For strong rock foundations, the depth of grouting holes is typically what percentage of the upstream water head?
a) 10–20%
b) 30–40%
c) 50–60%
d) 70–80%

Answer: b
Explanation: In strong rock foundations, grouting holes are generally drilled to a depth of 30–40% of the upstream water head.

In the case of poor rock foundations, the grouting hole depth may be as much as what percentage of the water pressure head?
a) 30–40%
b) 50–60%
c) 70%
d) 90%

Answer: c
Explanation: For poor rock conditions, the grouting depth may reach up to 70% of the water pressure head.

The grouting pressure during high-pressure grouting is generally expressed as 2.5 D N/cm². In this expression, what does "D" represent?
a) The diameter of the drilled hole
b) The depth of grouting (in meters) below the surface
c) The density of the grout
d) The distance between holes

Answer: b
Explanation: In the expression 2.5 D N/cm², "D" represents the depth of grouting in meters.

High-pressure grouting is typically performed in stages of approximately what depth each?
a) 5 m
b) 10 m
c) 15 m
d) 20 m

Answer: c
Explanation: Grouting is usually carried out in stages of about 15 m depth.

Curtain grouting may be accomplished from which of the following access points?
a) Only the foundation gallery
b) Only the upstream face of the dam
c) Only from tunnels in the foundation rock
d) From the foundation gallery, upstream face, or tunnels depending on the case

Answer: d
Explanation: Depending on the situation, grouting may be done from the foundation gallery, the upstream face, or tunnels driven into the foundation rock.

Which of the following is NOT typically a component of the drainage filter system in an earth dam?
a) Rock toe protection
b) Horizontal blanket
c) Chimney drain
d) Vertical reinforcement

Answer: d
Explanation: The drainage filter system includes rock toe protection, horizontal blankets, and chimney drains—not vertical reinforcement.

Installing an impervious cutoff to 50% of the foundation depth in an earth dam typically reduces discharge by what percentage?
a) 10%
b) 25%
c) 50%
d) 65%

Answer: b
Explanation: A cutoff installed to 50% depth reduces discharge by about 25%.

When an impervious cutoff is installed to 90% of the foundation depth, the discharge is reduced by approximately:
a) 25%
b) 40%
c) 65%
d) 80%

Answer: c
Explanation: A cutoff at 90% depth reduces discharge by roughly 65%.

Relief wells and drain trenches are constructed in an earth dam primarily to control:
a) Overtopping
b) Large-scale seepage that can cause sand boiling near the dam toe
c) Structural cracking
d) Ice formation

Answer: b
Explanation: Relief wells and drain trenches help control excessive seepage that may result in boiling of water (sand boiling) near the dam toe.

What is the primary function of a spillway in a dam?
a) To store excess water
b) To create recreational water areas
c) To safely pass excess water when the reservoir is full
d) To generate hydroelectric power

Answer: c
Explanation: A spillway is designed to safely discharge excess water when the reservoir reaches full capacity.

Which spillway type is defined as one that uses pressure to pass water?
a) Pressure spillway
b) Non-pressure spillway
c) Ogee spillway
d) Chute spillway

Answer: a
Explanation: Pressure spillways (which include shaft, siphon, and submerged types) are defined by their use of pressure to pass water.

Which spillway consists of a vertical shaft followed by a horizontal conduit and is also known as a Morning Glory or Bell Mouth spillway?
a) Chute spillway
b) Siphon spillway
c) Shaft spillway
d) Tunnel spillway

Answer: c
Explanation: A shaft spillway has a vertical shaft and horizontal conduit and is commonly referred to as a Morning Glory or Bell Mouth spillway.

The design of an ogee spillway is based on shaping the downstream face of the weir to mimic which feature?
a) The river bed profile
b) The lower nappe of a freely falling water jet
c) The dam’s crest line
d) The upstream water surface

Answer: b
Explanation: An ogee spillway’s profile mimics the ogee-shaped lower nappe formed by the freely falling water jet.

In a side channel spillway, after spilling from its crest, the water is diverted in which direction?
a) Downward in a straight line
b) At a 45° angle
c) Turned 90° to flow parallel to the crest
d) Reversed back into the reservoir

Answer: c
Explanation: In a side channel spillway, water spilling from the crest is turned 90° so that it flows parallel to the crest.

A straight drop spillway is typically reinforced by which additional structure to prevent downstream scouring?
a) Riprap
b) A reinforced concrete wall
c) An artificial pool with a concrete apron and a low secondary dam
d) Vegetative cover

Answer: c
Explanation: To prevent scouring, a straight drop spillway is often accompanied by an artificial pool with a concrete apron and a low secondary dam.

How is surplus water discharged in a chute (trough/open channel) spillway?
a) Through a vertical shaft
b) Through a steeply sloped open channel
c) Via a siphon action
d) Via an underground passage

Answer: b
Explanation: Chute spillways dispose of surplus water through a steeply sloped open channel.

A siphon spillway operates by which mechanism?
a) Gravity-only flow
b) Siphonic action through an inverted U-shaped conduit
c) Mechanical gating
d) Electric pumping systems

Answer: b
Explanation: A siphon spillway uses an inverted U-shaped conduit to generate siphonic action that discharges surplus water.

What is the primary function of a hydraulic jump stilling basin at the toe of a spillway?
a) To increase water velocity
b) To dissipate excess energy by forming a hydraulic jump
c) To store water temporarily
d) To filter debris from the water

Answer: b
Explanation: The stilling basin dissipates the kinetic energy of the high-velocity water by inducing a hydraulic jump.

When is a roller bucket typically used for energy dissipation on a spillway?
a) When the tail water depth is less than the post-jump depth
b) When the tail water depth is much greater than the post-jump depth
c) When no hydraulic jump is formed
d) During very low flow conditions only

Answer: b
Explanation: A roller bucket is used when the tail water is deep relative to the post-jump depth in order to dissipate energy effectively.

A deflector (flip bucket, ski jump, or trajectory bucket) is employed when:
a) Tail water depth is adequate for a hydraulic jump
b) Tail water depth is insufficient for forming a hydraulic jump
c) Water velocity is extremely low
d) The spillway is equipped with mechanical gates

Answer: b
Explanation: Deflector buckets are used when the tail water is too shallow to create a hydraulic jump, deflecting the jet to dissipate energy.

In determining the selection of an energy dissipator, if the TW curve coincides with the Y2 curve, which approach is most suitable?
a) Roller bucket
b) Hydraulic jump stilling basin with a concrete apron
c) Deflector bucket
d) No energy dissipator is needed

Answer: b
Explanation: When the TW curve aligns with the Y2 curve, jump formation conditions are optimal for using a stilling basin with a concrete apron.

USBR Stilling Basin Type IV is used for flow conditions where the Froude number is within which range?
a) Greater than 4.5
b) Between 2.5 and 4.5
c) Less than 2.5
d) Froude number is not a factor

Answer: b
Explanation: Type IV stilling basins are designed for flows with Froude numbers in the range of 2.5 to 4.5.

Stop-log or flash boards used in dam gating are typically made of:
a) Plastic
b) Timber, steel, or concrete beams
c) Fiberglass
d) Aluminum

Answer: b
Explanation: Stop-log or flash boards are commonly constructed from timber, steel, or concrete beams.

Vertical lift gates in dam structures typically operate by moving in which direction?
a) Horizontally
b) Vertically
c) Diagonally
d) In a circular path

Answer: b
Explanation: Vertical lift gates are designed to move vertically within a groove between two piers.

What is the defining feature of radial gates in dam design?
a) They are rectangular
b) They are hinged and follow a circular arc
c) They slide horizontally
d) They are fixed and do not move

Answer: b
Explanation: Radial gates are hinged with a curved, circular arc shape, with the hinge typically at the trunnion.

Ring gates are distinguished from radial gates by their operation as:
a) Fixed panels
b) Cylindrical drums that move vertically within an annular chamber
c) Sliding horizontally
d) Rotating valves

Answer: b
Explanation: Ring gates operate as cylindrical drums moving vertically in an annular hydraulic chamber to control water flow.

Sector gates are most commonly used in which of the following applications?
a) Hydropower penstock control
b) Navigation locks where water levels differ
c) Spillway energy dissipation
d) Seepage control systems

Answer: b
Explanation: Sector gates are typically used in navigation locks to control water flow between reservoirs at different elevations.

What is the primary function of a flap gate in dam design?
a) To regulate the main water flow
b) To remove floating debris from the river
c) To function as an emergency spillway
d) To support the dam structure

Answer: b
Explanation: Flap gates are used predominantly to clear floating debris from the river.

Deep seated vertical gates are primarily used for controlling water flow to which application?
a) Surface irrigation
b) Hydropower intakes
c) Recreational water features
d) Wastewater discharge

Answer: b
Explanation: Deep seated vertical gates are employed to regulate water flow toward hydropower intakes.

Cylindrical gates in dam design are primarily used for:
a) Decorative purposes
b) Shutting off water to penstocks or control valves in outlet works
c) Enhancing dam aesthetics
d) Providing walkway access

Answer: b
Explanation: Cylindrical gates are used to control water flow by shutting off water to penstocks or control valves.

Ring follower gates in dam design are primarily used as:
a) The main operational gate
b) Emergency gates that operate in fully closed or fully open positions
c) Decorative features on the dam face
d) Supplementary spillway controls

Answer: b
Explanation: Ring follower gates are designed as emergency gates that quickly move to either a completely open or closed position.

Which statement best describes the headworks of a run‐of‐river (ROR) plant?
a) It extends from the dam crest to the turbine
b) It extends from the weir/barrage to the settling basin to withdraw sediment‐free water
c) It stores water for later use
d) It functions as the powerhouse

Answer: b
Explanation: The headworks extend from the weir/barrage to the settling basin and are designed to withdraw the required amount of sediment‐free water.

What is the main purpose of the headworks in an ROR plant?
a) To provide storage for flood waters
b) To withdraw the required amount of water while controlling sediment, debris, ice, and trash
c) To generate electricity directly
d) To enhance evaporation losses

Answer: b
Explanation: The headworks are designed to withdraw the required sediment‐free water and to handle flood bypass, debris, bed load, and suspended particles.

Which of the following is NOT a requirement for a functional ROR headwork?
a) Withdrawal of the required water amount
b) Flood bypass capability
c) Control of bed load and debris
d) Maximization of hydraulic losses

Answer: d
Explanation: The headworks aim to minimize hydraulic losses, not maximize them.

What is the main function of the intake in a water-conveyance system?
a) To store water
b) To control and withdraw water from a reservoir or river into the system
c) To generate electricity
d) To dissipate excess energy from water flow

Answer: b
Explanation: The intake is the hydraulic structure that facilitates water withdrawal from the river or reservoir, feeding the water-conveying system.

While designing an intake, one of the primary considerations is to minimize:
a) Sediment deposition
b) Hydraulic (head) loss as water enters the system
c) Structural weight
d) Flood storage capacity

Answer: b
Explanation: The intake design must ensure minimal head loss as water flows into the water-conducting system.

To prevent air from being drawn into the water-conducting system, the intake design must minimize the formation of:
a) Sediment layers
b) Air vortices (from hydraulic jumps or high velocity)
c) Mechanical vibrations
d) Thermal losses

Answer: b
Explanation: Avoiding vortex formation at the intake is crucial so that air is not drawn into the system, which could cause cavitation.

The design discharge for an intake should be set to how much more than the turbine discharge?
a) 5-10% more
b) 10-20% more
c) 20-30% more
d) 30-40% more

Answer: b
Explanation: The design discharge is typically taken as 10–20% more than that of the turbine discharge to accommodate system variations.

The intake invert level is fixed based on which factor?
a) The height of the dam
b) Sediment content (bed load) and design experience
c) Ambient air temperature
d) The location of the powerhouse

Answer: b
Explanation: The intake invert level is determined primarily by the sediment load and site experience, generally set about 0.5 m or more above the under-sluice level.

What is the acceptable range for the entrance velocity at an intake system?
a) 0.1-0.3 m/s
b) 0.6-0.8 m/s (up to 1 m/s for small systems)
c) 1.5-2.0 m/s
d) Greater than 2 m/s

Answer: b
Explanation: The entrance velocity should be maintained between 0.6 and 0.8 m/s, though up to 1 m/s can be acceptable for small systems.

What is the recommended approach velocity for water entering the intake system?
a) 0.5 m/s
b) 1 m/s
c) 1.5 m/s
d) 2 m/s

Answer: b
Explanation: The approach velocity is generally recommended to be approximately 1 m/s.

The intake opening is typically designed as a broad-crested weir that can operate under which conditions?
a) Only under free-flow conditions
b) Only under submerged conditions
c) Under both submerged and free-flow conditions
d) Under gravitational forces only

Answer: c
Explanation: The intake opening is designed as a broad-crested weir which may operate under either submerged or free-flow conditions, depending on upstream and downstream water levels.

In the orifice flow equation for the intake opening, the constant “C” depends on:
a) The quality and finish of the opening
b) The chemical composition of water
c) The height of the reservoir
d) The length of the weir

Answer: a
Explanation: The constant “C” depends on the shape and finish of the opening (e.g., 0.6 for roughly finished, and 0.8 for carefully finished openings).

Which losses should be included in the hydraulic loss calculation for an intake structure?
a) Trash rack loss
b) Entrance loss
c) Transition and gate loss
d) All of the above

Answer: d
Explanation: Hydraulic loss calculations should account for trash rack, entrance, transition, and gate losses.

To prevent air entrainment at the intake, the following relation is used:
a) s × v × d > C
b) s / (v × d) > C
c) (v × d) / s > C
d) s + v + d > C

Answer: b
Explanation: The design ensures that s / (v × d) is greater than a constant (C) to avoid vortex formation and subsequent air entry, where s is submergence, v is velocity, and d is conduit diameter.

What is the main purpose of providing an air vent in the intake system?
a) To increase water speed
b) To prevent cavitation by releasing trapped air
c) To filter sediments
d) To support the inlet structure

Answer: b
Explanation: Air vents are provided to allow trapped air to escape, thereby preventing cavitation within the conduit.

Which factor is NOT a primary consideration when determining the location of an intake?
a) Adequate inflow and low silt content
b) Minimal head loss
c) Least environmental impact
d) Proximity to urban centers

Answer: d
Explanation: The intake location is based on hydraulic, sediment, and environmental factors rather than the proximity of urban centers.

For run-of-river plants, which intake configurations may be used?
a) Side (lateral) intake
b) Frontal intake
c) Drop intake
d) All of the above

Answer: d
Explanation: Depending on the layout and river conditions, ROR plants may use side, frontal, or drop intakes.

What is the primary function of a trash rack in an intake design?
a) To reinforce the inlet structure
b) To trap large debris such as logs, boulders, and branches
c) To accelerate the flow of water
d) To adjust the water level

Answer: b
Explanation: The trash rack prevents coarse river-borne materials from entering the water-conducting system.

Why is it important to minimize sediment entry in the intake system?
a) To protect the turbines and ensure efficient operation
b) To increase water temperature
c) To improve water clarity for recreational use
d) It is not important

Answer: a
Explanation: Minimizing sediment entry is crucial for protecting hydraulic machinery and ensuring the efficient operation of the system.

In intake design, how is the contraction loss due to pier or abutment effects typically accounted for?
a) The effective opening length is taken as 0.5 times the actual opening
b) The effective opening length is taken as 0.9–0.95 times the actual opening
c) It is ignored in design calculations
d) The opening is increased arbitrarily

Answer: b
Explanation: Designers typically consider the effective length of the opening to be 90–95% of the actual opening to account for contraction losses.

Which factor is most important when selecting the type of intake for a ROR plant?
a) The architectural appearance of the structure
b) Site hydraulic conditions and local fluid behavior
c) The color of construction materials
d) The age of the dam

Answer: b
Explanation: The intake type is selected based on site-specific hydraulic conditions (such as water flow, sediment concentration, and debris potential), rather than aesthetic or age considerations.

In intake design, the intake invert level is primarily fixed based on which factor?
a) The prevailing air temperature
b) Sediment (bed load) content and construction experience
c) The color of the river water
d) The design of the turbine house

Answer: b
Explanation: The intake invert level is set considering the sediment content (bed load) and past construction experience, often about 0.5 m (or more) above the under-sluice level.

What is the recommended range for the trash velocity at the intake to prevent debris entry?
a) 0.2–0.4 m/s
b) 0.6–0.75 m/s
c) 1.0–1.2 m/s
d) 1.5–2.0 m/s

Answer: b
Explanation: To minimize the entry of debris into the conveyance system, the trash velocity is maintained within 0.6–0.75 m/s.

How is the contraction loss due to pier or abutment effects typically accounted for in intake design?
a) The effective opening is assumed to be 0.5 times the actual opening
b) The effective opening length is taken as 0.9–0.95 times the actual opening
c) It is ignored in design calculations
d) It is doubled for safety calculations

Answer: b
Explanation: Designers typically account for contraction loss by using an effective opening length that is 90–95% of the measured physical opening.

The intake opening is generally designed as a broad-crested weir. Under which conditions can it operate?
a) Only under free-flow conditions
b) Only under submerged conditions
c) Under both submerged and free-flow conditions
d) Only during high flow events

Answer: c
Explanation: The broad-crested weir-type intake opening is designed to function efficiently in either submerged or free-flow scenarios, depending on water levels upstream and downstream.

Which of the following losses is NOT normally included when calculating hydraulic losses in an intake system?
a) Trash rack loss
b) Entrance loss
c) Transition loss
d) Thermal loss

Answer: d
Explanation: Hydraulic loss calculations consider trash rack, entrance, transition, and gate losses; thermal losses are not typically a design factor.

To prevent air entrainment at the intake, the following relation is used:
a) s × v × d > C
b) s / (v × d) > C
c) (v × d) / s > C
d) s + v + d > C

Answer: b
Explanation: The design ensures that the ratio s / (v × d) (where s is the submergence, v is the velocity, d is the conduit diameter) exceeds a constant (C) to avoid vortex formation and air entrainment.

What is the primary purpose of incorporating air vents in the intake system?
a) To elevate the water temperature
b) To release trapped air and prevent cavitation
c) To inject air into the water for aeration
d) To support debris removal

Answer: b
Explanation: Air vents are provided to release entrapped air, prevent cavitation, and maintain the efficiency of the water-conducting system.

Which of the following is NOT a primary consideration when selecting the location of an intake?
a) Adequate inflow and low silt content
b) Minimal head loss
c) Least environmental impact
d) Aesthetic appeal of the intake structure

Answer: d
Explanation: While hydraulic and sediment criteria are crucial, the aesthetic appeal of the intake is not a primary design consideration.

Why is it critical to limit the water velocity at the entrance of the intake system?
a) To increase turbulence for better mixing
b) To ensure a smooth, turbulence-free, vortex-free water entry and reduce head loss
c) To facilitate faster water conveyance
d) To allow for higher sediment transport

Answer: b
Explanation: Limiting the entrance velocity minimizes turbulence and the formation of vortices, ensuring smooth water entry and reducing hydraulic losses.

What is the primary objective of a settling basin (desander) in a hydropower plant?
a) To store water for peak demand
b) To remove suspended particles that cause wear on turbines and accessories
c) To increase the reservoir level
d) To generate additional electricity

Answer: b
Explanation: The main purpose of a settling basin is to remove suspended particles that could otherwise wear down turbines and related equipment.

Settling basins can be classified based on which of the following criteria?
a) Flushing system and prominent features
b) Water temperature and color
c) Location relative to the powerhouse
d) Type of turbine used

Answer: a
Explanation: They are classified based on the flushing system (periodic versus continuous) and their prominent features/design methods.

What is the advantage of a periodic type settling basin based on its flushing system?
a) No loss of water
b) No generation loss
c) Continuous operation without interruption
d) Fully automated flushing

Answer: a
Explanation: A periodic type settling basin is designed so that there is no loss of water during the non-flushing period.

What is a major disadvantage of the continuous type settling basin?
a) Generation loss during flushing
b) Continuous loss of water during flushing
c) Inability to remove sediments
d) High mechanical complexity

Answer: b
Explanation: Continuous type settling basins suffer from a continuous loss of water during the flushing process.

In a conventional type settling basin, how is the deposited sediment typically removed?
a) Automatically through a continuous mechanical system
b) Manually or with mechanical equipment after dewatering or by lowering the water level to create a rapid gravity flow
c) By using centrifugal forces
d) Through the use of hydrocyclones exclusively

Answer: b
Explanation: In conventional settling basins, sediment removal is often done manually or mechanically after dewatering; sometimes lowering the water level generates a swift gravity flow which flushes out the sediment.

The Bieri type settling basin is characterized by the use of two horizontal shutters. What is the function of the upper shutter?
a) It remains permanently fixed
b) It moves horizontally over the fixed lower shutter once sediment reaches a desired level to flush it out
c) It cools the water for turbine efficiency
d) It acts as a secondary intake

Answer: b
Explanation: In the Bieri type, the upper shutter moves horizontally over a fixed lower shutter to flush out accumulated sediment when it reaches a specified level.

What is the unique feature of the Serpent Sediment Sluicing System (S4) in a settling basin?
a) It uses manual scrubbing tools
b) It employs a float unit (serpent) that operates under gravity, requiring no machinery or energy input
c) It continuously recirculates water without flushing sediment
d) It relies on chemical coagulation to settle sediments

Answer: b
Explanation: The S4 system uses a buoyant float unit (the serpent) that covers and then uncovers the flushing channel as needed, operating entirely under gravity.

What is one significant advantage of using the S4 system in a settling basin?
a) It requires additional electrical energy
b) It operates solely under gravity, reducing operational costs and energy use
c) It eliminates the need for sediment removal
d) It increases water loss during flushing

Answer: b
Explanation: The S4 system’s use of a float device under gravity means no extra machinery or energy is required, thereby reducing operational costs.

The Split & Settle method in settling basins is based on which principle?
a) Diverting the top clean water for sediment removal
b) Diverting the lower, sediment-laden water to a settling tunnel while conveying relatively clean water to the powerhouse
c) Mixing all water layers uniformly
d) Increasing the overall sediment concentration in the basin

Answer: b
Explanation: In the Split & Settle method, the denser, sediment-rich bottom layer is diverted to a settling tunnel while the cleaner upper layer continues to the powerhouse.

Which physical principle does a hydrocyclone primarily use to separate sediment from water?
a) Gravitational settling
b) Centrifugal force
c) Magnetic separation
d) Filtration through screens

Answer: b
Explanation: A hydrocyclone uses centrifugal force to separate denser sediment particles from the water by forcing them to move in a helicoidal path toward an orifice.

What range of particle sizes is typically removed by a hydrocyclone?
a) 1–10 μm
b) 5–300 μm
c) 500–1000 μm
d) Greater than 1 mm

Answer: b
Explanation: Hydrocyclones are generally designed to remove particles in the range of 5 to 300 μm from the water.

The Hooper type settling basin is best described as a:
a) Periodic flushing system
b) Continuous flushing type where sediment is removed continuously from a bottom opening
c) System that uses chemical additives to precipitate sediment
d) Gravity-driven type with no exit for sediment

Answer: b
Explanation: The Hooper type is a continuous flushing settling basin where deposited sediment is removed continuously from a bottom opening.

One disadvantage of the periodic type settling basin is that it:
a) Loses water continuously
b) Suffers generation loss during flushing
c) Requires extensive mechanical equipment
d) Has no sediment removal capability

Answer: b
Explanation: While the periodic type does not lose water during normal operation, it suffers a generation loss during the flushing process.

What is the primary disadvantage of a continuous type settling basin?
a) Generation loss during flushing
b) Continuous loss of water during flushing
c) Requires manual sediment removal
d) High installation cost

Answer: b
Explanation: The continuous type is designed to avoid generation loss, but it suffers from a continuous loss of water while flushing.

In a Bieri type settling basin, what triggers the flushing of accumulated sediment?
a) A manual valve adjustment
b) The movement of the upper horizontal shutter over the lower fixed shutter once the sediment reaches a predetermined level
c) A sensor that detects water turbidity
d) A continuous mechanical scraper

Answer: b
Explanation: In the Bieri type, the upper shutter moves horizontally over a fixed lower shutter, flushing the sediment when its accumulation reaches the desired level.

What is a key advantage of the Serpent Sediment Sluicing System (S4) compared to other designs?
a) It requires external power for operation
b) It operates automatically under gravity without any additional machinery or energy input
c) It minimizes sediment removal
d) It is more complex to operate than the Bieri type

Answer: b
Explanation: The S4 system is advantageous because it uses a buoyant serpent float to automatically open and close the flushing channel under gravity, without the need for external energy.

What is the primary benefit of the split & settle method in settling basin design?
a) It entirely eliminates the need for a settling basin
b) It diverts the dirtiest (bottom layer) water to a settling tunnel while conveying cleaner (upper layer) water to the powerhouse, thus saving construction costs
c) It increases overall sediment concentration
d) It uses chemical additives to dissolve sediments

Answer: b
Explanation: The split & settle method diverts the sediment-rich, lower layer to a settling tunnel while allowing cleaner water to continue to the powerhouse, thereby reducing the need (and cost) for a full-scale settling basin.

In a hydrocyclone, what is the purpose of the vortex finder (overflow pipe extension)?
a) To increase water velocity
b) To prevent short-circuiting of the feed directly to the overflow
c) To mix sediments with water
d) To maintain constant water temperature

Answer: b
Explanation: The vortex finder is used to prevent the incoming flow from directly short-circuiting to the overflow, ensuring proper sediment separation.

What shapes define a typical hydrocyclone design?
a) A rectangular vessel with vertical baffles
b) A conical vessel joined to a cylindrical section with a tangential feed inlet
c) A purely spherical container
d) A flat open channel

Answer: b
Explanation: A typical hydrocyclone is designed with a conical section attached to a cylindrical section, along with a tangential feed inlet to generate the required vortex.

The Hooper type settling basin is best exemplified by which continuous flushing system?
a) A system that requires periodic shutdown for sediment removal
b) A continuous flushing type where sediment is removed from a bottom opening
c) A system that uses chemical coagulation
d) A siphon-based system

Answer: b
Explanation: The Hooper type settling basin continuously flushes out sediment through a bottom opening without interrupting the operation.

In the laminar regime (Re < 1), which equation correctly represents the settling velocity for a small, spherical particle (Stokes' Law)?
a) \(v_s = \frac{g\,(\rho_p - \rho)d^2}{18\,\mu}\)
b) \(v_s = \frac{g\,(\rho_p - \rho)d}{18\,\mu}\)
c) \(v_s = \frac{g\,(\rho_p - \rho)d^3}{18\,\mu}\)
d) \(v_s = \frac{g\,(\rho_p + \rho)d^2}{18\,\mu}\)

Answer: a
Explanation: Stokes’ Law for a small, spherical particle in a laminar regime (Re < 1) is given by \(v_s = \frac{g\,(\rho_p - \rho)d^2}{18\,\mu}\).

Expressing settling velocity using kinematic viscosity (\(\nu = \mu/\rho\)) and the relative density (\(s = \rho_p/\rho\)), which equation represents \(v_s\)?
a) \(v_s = \frac{g\,d^2}{18\,\nu}\)
b) \(v_s = \frac{g\,(s-1)d^2}{18\,\nu}\)
c) \(v_s = \frac{18\,\nu\,(s-1)}{g\,d^2}\)
d) \(v_s = \frac{g\,(1-s)d^2}{18\,\nu}\)

Answer: b
Explanation: Using kinematic viscosity and relative density, the settling velocity is given by \(v_s = \frac{g\,(s-1)d^2}{18\,\nu}\).

Under turbulent conditions, which formula correctly estimates the settling velocity for larger particles?
a) \(v_s = \frac{4\,g\,(\rho_p - \rho)d}{3\,C_d\,\rho}\)
b) \(v_s = \frac{4\,g\,(\rho_p - \rho)d^2}{3\,C_d\,\rho}\)
c) \(v_s = \frac{g\,(\rho_p - \rho)d}{3\,C_d\,\rho}\)
d) \(v_s = \frac{4\,g\,(\rho_p - \rho)d}{C_d\,\rho}\)

Answer: a
Explanation: For the turbulent regime, the settling velocity is estimated by \(v_s = \frac{4\,g\,(\rho_p - \rho)d}{3\,C_d\,\rho}\), where \(C_d\) is the drag coefficient.

Which expression defines the particle Reynolds number (\(Re\)) based on the settling velocity?
a) \(Re = \frac{\rho\,v_s\,d}{\mu}\)
b) \(Re = \frac{v_s\,d}{\nu}\)
c) \(Re = \frac{v_s^2\,d}{\nu}\)
d) \(Re = \frac{g\,d}{\nu}\)

Answer: b
Explanation: The particle Reynolds number is defined as \(Re = \frac{v_s\,d}{\nu}\).

For particles where \(Re < 1\), which expression correctly represents the drag coefficient (\(C_d\))?
a) \(C_d = \frac{24}{Re}\)
b) \(C_d = \frac{12}{Re}\)
c) \(C_d = \frac{24}{Re(1+0.15\,Re^{0.687})}\)
d) \(C_d = 0.44\)

Answer: a
Explanation: For \(Re < 1\), the drag coefficient is defined by \(C_d = \frac{24}{Re}\).

For the range \(1 \le Re \le 1000\), which expression correctly defines the drag coefficient (\(C_d\))?
a) \(C_d = \frac{24}{Re}\)
b) \(C_d = \frac{24}{Re(1+0.15\,Re^{0.687})}\)
c) \(C_d = 0.44\)
d) \(C_d = \frac{12}{Re}\)

Answer: b
Explanation: For \(1 \le Re \le 1000\), the empirical formula for the drag coefficient is \(C_d = \frac{24}{Re(1+0.15\,Re^{0.687})}\).

For Reynolds numbers greater than 1000 (\(Re > 1000\)), what is the recommended value for the drag coefficient (\(C_d\))?
a) \(C_d = 0.44\)
b) \(C_d = \frac{24}{Re}\)
c) \(C_d = \frac{24}{Re(1+0.15\,Re^{0.687})}\)
d) \(C_d = \frac{12}{Re}\)

Answer: a
Explanation: For \(Re > 1000\), experimental data suggest that \(C_d \approx 0.44\).

An empirical relation for settling velocity is given by \(v_s = a\,d^{0.7}\) (with \(v_s\) in cm/s and \(d\) in mm). For particles with \(d > 1\) mm, what is the approximate value of \(a\)?
a) 36
b) 44
c) 51
d) 60

Answer: a
Explanation: Empirical data indicate that for \(d > 1\) mm, the coefficient \(a \approx 36\).

Which equation represents the continuity equation for steady, uniform flow in a settling basin?
a) \(Q = B\,h\,v\)
b) \(Q = B + h + v\)
c) \(Q = \frac{B}{h\,v}\)
d) \(Q = \frac{B\,h}{v}\)

Answer: a
Explanation: The continuity equation is \(Q = B\,h\,v\), where \(B\) is the basin width, \(h\) its depth, and \(v\) the velocity.

What equation is used to calculate the sediment load entering the settling basin?
a) Sediment Load = \(Q\,T\,C\)
b) Sediment Load = \(Q + T + C\)
c) Sediment Load = \(\frac{Q}{T\,C}\)
d) Sediment Load = \(Q\,C\)

Answer: a
Explanation: The sediment load is calculated as \( \text{Sediment Load} = Q\,T\,C \), where \(T\) is the detention time and \(C\) is the sediment concentration.

Given the sediment deposit volume \(V_s\) in a basin with plan area \(L \times B\), which formula calculates the deposition depth (\(d_{dep}\))?
a) \(d_{dep} = \frac{V_s}{L\,B}\)
b) \(d_{dep} = V_s \times L \times B\)
c) \(d_{dep} = \frac{L\,B}{V_s}\)
d) \(d_{dep} = \frac{V_s\,\rho_s}{L\,B}\)

Answer: a
Explanation: The deposition depth is given by \(d_{dep} = \frac{V_s}{L\,B}\), where \(V_s\) is the sediment volume and \(L \times B\) is the basin’s plan area.

Which of the following best describes a hydraulic tunnel?
a) A surface water pipeline
b) An underground water conduit formed by excavation without disturbing the surface
c) An aerial water channel
d) A tunnel designed exclusively for vehicular traffic

Answer: b
Explanation: A hydraulic tunnel is an underground water conduit excavated without disturbing the surface.

Which of the following is an advantage of hydraulic tunnels?
a) Increased environmental impact due to land acquisition
b) Reduced head loss by adopting the shortest possible route
c) Higher construction risk compared to surface lines
d) Longer construction period than conventional methods

Answer: b
Explanation: Hydraulic tunnels adopt the shortest possible route, resulting in minimal head loss and less environmental disturbance.

Hydraulic tunnels are particularly useful in which type of terrain?
a) Flat, urban areas
b) Rugged, mountainous regions
c) Desert areas
d) Coastal plains

Answer: b
Explanation: In rugged or mountainous terrain, constructing a surface line is difficult, making underground hydraulic tunnels the preferred choice.

Which form of hydraulic tunnel is used to connect reservoirs?
a) Spillway tunnel
b) Diversion tunnel
c) Interconnection tunnel
d) Navigational tunnel

Answer: c
Explanation: An interconnection tunnel links reservoirs, allowing water to be conveyed between them.

In a non-pressure tunnel, the water flow is typically characterized by:
a) Pressurized pipe flow
b) Open channel flow with a free surface exposed to the atmosphere
c) Fully sealed flow
d) Turbulent closed-conduit flow

Answer: b
Explanation: In non-pressure tunnels, flow occurs as an open channel with a free surface open to atmospheric conditions.

Which hydraulic design principle is most applicable for a pressure flow tunnel?
a) Manning's equation
b) Darcy–Weisbach equation
c) Bernoulli’s equation
d) Continuity equation

Answer: b
Explanation: The Darcy–Weisbach equation is used to compute head loss in pressurized tunnels.

The head loss in a pressure tunnel is calculated using which of the following formulas?
a) hf = (n.l.v²)/(2gd)
b) hf = (f.l.v²)/(2gd)
c) hf = (f.l.v)/(2gd)
d) hf = (n.l.v)/(2gd)

Answer: b
Explanation: In pressure tunnels, the head loss is calculated using the Darcy–Weisbach friction factor in the formula hf = (f.l.v²)/(2gd).

The maximum recommended water velocity in an unlined hydraulic tunnel is approximately:
a) 1–1.5 m/s
b) 2–2.5 m/s
c) 3–3.5 m/s
d) 4–4.5 m/s

Answer: b
Explanation: For unlined tunnels the recommended maximum water velocity is generally between 2 to 2.5 m/s.

What is the empirical formula to calculate the thickness of tunnel lining (in mm) given the tunnel diameter (D) in meters?
a) Thickness = 82 × D
b) Thickness = 82 / D
c) Thickness = 82 + D
d) Thickness = D - 82

Answer: a
Explanation: The empirical formula to determine the thickness of tunnel lining is given by Thickness = 82 × D.

Which tunnel cross-sectional shape is most suitable when there is high internal pressure and surrounding rock quality is poor?
a) Circular Section
b) D-shaped Section
c) Horse-Shoe Section
d) Rectangular Section

Answer: a
Explanation: The circular section is structurally most suitable to withstand high internal pressures especially when the surrounding rock is of poor quality.

Which cross-sectional shape is considered a compromise between structural strength and ease of construction, and is often preferred in tunnel design?
a) Circular Section
b) D-shaped Section
c) Horse-Shoe Section
d) Elliptical Section

Answer: c
Explanation: The horse-shoe section provides a good compromise between ease of construction and the ability to withstand external rock and water pressures.

The New Austrian Tunnel Method (NATM) is best described as:
a) A method that relies solely on heavy machinery for excavation
b) A construction strategy that utilizes the strength of the surrounding rock and soil
c) An outdated tunneling technique used only in the past
d) A process that exclusively employs full face blasting

Answer: b
Explanation: NATM is a flexible design philosophy that leverages the inherent strength of the surrounding ground to stabilize the tunnel.

Which tunneling method involves excavating a smaller portion (heading) first and then enlarging it to the full tunnel size?
a) Full face blasting
b) Tunnel Boring Machine (TBM)
c) Heading and Benching
d) Cut and Cover Method

Answer: c
Explanation: The heading and benching method involves first excavating a small portion and then enlarging it to the required cross-sectional area.

Which of the following is NOT a benefit of tunnel lining?
a) Increases hydraulic capacity by reducing friction losses
b) Provides structural support to the tunnel
c) Keeps the tunnel free from water percolation
d) Increases the tunnel's cross-sectional area beyond design limits

Answer: d
Explanation: Tunnel lining is intended to enhance structural stability and reduce hydraulic losses, not to increase the cross-sectional area beyond what is designed.

Why should tunnel alignment be as straight as possible?
a) To reduce construction cost and head loss that occur with bends
b) Because curved tunnels are more aesthetically pleasing
c) To facilitate the use of a Tunnel Boring Machine exclusively
d) Because alignment has no significant impact on tunnel performance

Answer: a
Explanation: A straight tunnel alignment minimizes construction costs and head loss, as bends can lead to increased resistance and higher expenses.

Which of the following is a drawback of hydraulic tunnels?
a) Minimal environmental impact
b) Reduced seismic effects due to increased depth
c) High construction costs and risks
d) Optimal consumption of space

Answer: c
Explanation: Hydraulic tunnels, while beneficial in many respects, tend to have high construction costs and associated risks.

Which of the following factors is NOT typically considered when designing a hydraulic tunnel?
a) Discharge requirements
b) Seismic effects
c) Aesthetic appeal of tunnel lining
d) Quality and strength of surrounding rock

Answer: c
Explanation: Tunnel design primarily focuses on hydrodynamic, geological, and structural factors, not on the aesthetic appeal of the lining.

In tunnel construction, what is the primary purpose of installing rock bolts?
a) To increase the excavation speed
b) To provide temporary support and stabilize the tunnel roof
c) To measure water flow velocity
d) To reduce the tunnel lining thickness

Answer: b
Explanation: Rock bolts are used to support and stabilize the tunnel until the permanent lining is installed.

Which of the following best describes a primary purpose of tunnel lining?
a) To expand the tunnel’s cross-sectional area
b) To support the structure, reduce water leakage, and minimize friction losses
c) To delay the tunnel’s operational start
d) To increase the weight of the tunnel

Answer: b
Explanation: Tunnel lining is applied to give the tunnel the correct shape, support its structure, prevent water infiltration, and reduce flow resistance.

Which tunneling technique uses pre-made concrete segments that are assembled inside the tunnel?
a) Shotcrete lining
b) Precast concrete segment lining
c) Cast-in-place concrete lining
d) Steel liner plating

Answer: b
Explanation: Precast concrete segment lining employs segments made offsite which are then assembled in the tunnel to form a continuous lining.

The New Austrian Tunnel Method (NATM) is primarily based on:
a) Relying exclusively on mechanical excavation methods
b) Utilizing the inherent strength of the surrounding rock along with continuous support adjustments
c) Installing a full tunnel lining before excavation
d) Using only full face blasting throughout construction

Answer: b
Explanation: NATM leverages the strength of the surrounding ground and uses continuous monitoring to decide on appropriate support, adapting as conditions change.

Why might an engineer choose full face blasting over heading and benching?
a) It is more suitable for variable, weak soil conditions
b) It allows for uniform excavation of the entire tunnel section, which is ideal in strong rock conditions
c) It minimizes noise pollution
d) It avoids the need for any tunnel support

Answer: b
Explanation: Full face blasting excavates the complete tunnel cross-section uniformly and is typically used in strong, well-conditioned rock where speed is prioritized.

In a free flow tunnel, discharge is calculated using Manning's equation. Which parameter is NOT included in Manning's equation?
a) Cross-sectional area (A)
b) Hydraulic radius (R)
c) Slope (S)
d) Acceleration due to gravity (g)

Answer: d
Explanation: Manning's equation includes the roughness coefficient (n), cross-sectional area (A), hydraulic radius (R), and slope (S), but not the acceleration due to gravity.

Which of the following statements is true regarding the use of Tunnel Boring Machines (TBM) in tunnel construction?
a) TBMs are generally less expensive than other methods
b) TBMs are ideal for long tunnels because they provide a fast and safe excavation process
c) TBMs are only suitable for shallow tunnels
d) TBMs eliminate the need for any lining or support systems

Answer: b
Explanation: Although TBMs are expensive, they offer a fast, efficient, and safe method for excavating long tunnels, especially in uniform ground conditions.

Which method is best described as excavating a trench from the surface, constructing a tunnel, and then restoring the surface?
a) Drilling and Blasting
b) Cut and Cover Method
c) Tunnel Boring Machine (TBM)
d) Heading and Benching

Answer: b
Explanation: The Cut and Cover method involves excavating a shallow trench from the surface, constructing the tunnel, and then covering it, effectively restoring the surface.

What does the term "Bridge Action Period" in tunnel engineering refer to?
a) The interval during which tunnel lining is applied
b) The time between excavation (blasting) and the onset of roof collapse in an unsupported tunnel
c) The duration of water flow tests
d) The time required for installing tunnel support devices

Answer: b
Explanation: The Bridge Action Period is the time elapsed between excavation and the moment when the unsupported tunnel roof begins to collapse, indicating the urgency for additional support.

Why do hydraulic tunnels often experience minimal head loss compared to surface channels?
a) Because they are always constructed with a smooth concrete lining
b) Because they adopt the shortest possible route, reducing the length of the flow path
c) Because they always use circular cross-sections
d) Because the water is always under high pressure

Answer: b
Explanation: Hydraulic tunnels are designed to follow the shortest route possible, which minimizes head loss since the flow path is shorter and more direct.

Tunneling is required in case of ____________
a) Laying pavement
b) Laying road
c) On ground passage
d) Underground passage

Answer: d
Explanation: Tunnel can be defined as artificial underground passage, which is created for different purposes. It is required in case of highways, railways, sewerage and water supply.

The line at which the tunnel wall breaks from sloping outward can be given as _________
a) Spring line
b) Oval line
c) Centre line
d) Middle line

Answer: a
Explanation: Spring line is determined as the line at which the wall breaks from sloping outward to sloping inward toward the crown. This acts as a barrier between the outward and inward regions.

Which of the following should be considered while aligning a tunnel?
a) Atmospheric conditions
b) Hydrological conditions
c) Climatic conditions
d) Surface limits

Answer: b
Explanation: The determination of the alignment for tunnel can be done based on geological and hydrological conditions, cross-section and length of the continuous tunnel, time of consideration and limit of the surface.

Among the following, which doesn’t belong to tunnel classification?
a) Firm ground
b) Running ground
c) Rocky ground
d) Soft ground

Answer: c
Explanation: Tunneling has been classified based on the type of strata present. It includes firm ground, soft ground and running ground. These will determine the bearing capacity of the soil.

Which method can be adopted if full face excavation is not possible?
a) Back bearing method
b) Plotting
c) Trenching
d) Benching

Answer: d
Explanation: In case of no possibility of full face excavation, top heading method is adopted for having a better output. Benching process is also adopted for digging small tunnels.

Among the following, which can be adopted for providing support for soft strata?
a) Bents of aluminum
b) Bents of iridium
c) Bents of steel
d) Bents of plastic

Answer: c
Explanation: The provision of soft strata must be done for withstanding the excavation. It can be provided by bents of wood, bents of steel, liner plates and poling, which are placed to retain material between the adjacent bents.

A steel cylinder which is pushed in the soft soil is determined as ________
a) Jar born
b) Shield
c) Rod
d) Pole

Answer: b
Explanation: In the case of soft grounds, tunneling can be dangerous and cave-ins are common. To prevent this, an iron or steel cylindrical element called shield is placed in the soft soil, which can crave the hole perfectly.

Which method can be adopted in case of rock tunneling?
a) Full face method
b) Benching
c) Tracing
d) Back bearing method

Answer: a
Explanation: Rock tunneling involves the same principle as of the tunneling in the ground. Those include full face method, top heading method and drift method. Based on the conditions of the area, these can be adopted.

Which of the following can act as an alternative for blasting?
a) Tunneling
b) Continuous blasting
c) Sequential blasting
d) Fire-setting

Answer: d
Explanation: Blasting is the conventional method which is adopted in case of rock tunneling. In the case of fire-setting, tunnel is heated with fire and then cooled with water. Rapid expansion and contraction weakens and rock and tends to break.

Which of the following involves in the sequence of rocky strata?
a) Marking profile
b) Placing rocks
c) Improving foul gases
d) Recording values

Answer: a
Explanation: Rocky strata involve usage of blasting method for developing tunnels. The sequence contains marking profile, loading explosive, removing foul gases, checking, scaling, mucking and bolting.