1. The type of turbine used in hydro-electric plant for a water head range of 70 meter – 500 meter is:
A. Pelton
B. Kaplan
C. Francis
D. Propeller
Answer: C. Francis
Explanation:
In Francis Turbine the medium head is required generally in the range of (30-500) meter. In Kaplan Turbine very low head is required, generally less than 30-meter
In Francis Turbine medium flow rate is required. In Kaplan Turbine very large flow rate is required
High head turbine:
Explanation:
The main functions of the surge tank are:
1. When the load decreases, the water moves backward and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank.
3. The most efficient power plant is ______.
A. Hydroelectric power plant
B. Coal-based steam power plant
C. Nuclear power plant
D. Diesel engine power plant
Answer: A. Hydroelectric power plant
Explanation:
Power station VS Efficiency
Note:
4. Rammam hydroelectric power project is located in
A. Purulia
B. Bankura
C. Jalpaiguri
D. Darjeeling
Answer: D. Darjeeling
Explanation:
The correct answer is Darjeeling.
5. The advantage of hydro-electric power station over thermal power station is:
A. The initial cost of hydro-electric power station is low
B. The operating cost of hydro-electric power station is low
C. Hydro-electric power station can supply the power throughout the year
D. Hydro-electric power station can be constructed at the place where the energy is required
Answer: B. The operating cost of hydro-electric power station is low
Explanation:
A generating station which utilises the potential energy of water at a high level for the generation of electrical energy is known as a hydro-electric power station.
Advantages:
Disadvantages:
6. The hydraulic turbine suitable for a speed range of 95 to 440 rpm is:
A. Pelton wheel
B. Kaplan
C. Rankine
D. Francis
Answer: D. Francis
Explanation:
The specific speed of a turbine is defined as, the speed of a geometrically similar Turbine that would develop unit power when working under a unit head (1m head).
Low specific speed turbine:
Medium-specific turbine:
High specific turbine: the specific speed is more than 300 rpm. Example: Kaplan or propeller turbine
Reaction turbines are used for low and medium heads (usually less than 300 m) and for high discharge.
Flow VS Energy VS Head VS Specific speed VS Example
Tangential--Impulse--High head(300 m and above)--Low(0 – 60 RPM)--Pelton Wheel turbine
Radial--Reaction--Medium(30 m to 300 m)--Medium(60 – 300) RPM--Francis turbine
Axial--Reaction--Low(less than 30 m)--High(300 – 600) RPM--Propeller turbine(600 – 1000) RPM-Kaplan turbine
7. Which of the following scientific principles is mainly behind the generation of hydroelectric power?
A. Conversion of gravitational energy into electrical energy
B. Conversion of gravitational potential energy into thermal energy
C. Conversion of electrical energy into kinetic energy
D. Conversion of gravitational potential energy into electrical energy
Answer: D. Conversion of gravitational potential energy into electrical energy
Explanation:
The correct answer is the Conversion of gravitational potential energy into electrical energy.
Hydroelectric Power Plant:
8. Trash rack, forebay, surge tank, spill way are the terms involved with:
A. nuclear power plant
B. thermal power plant
C. wind turbine based power plant
D. hydroelectric power plant
Answer: D. hydroelectric power plant
Explanation:
Trash rack, forebay, surge tank, spill way are the terms involved with hydroelectric power plant.
Track Rask:
It is used in hydro-electric power plant to filter the water before it flows towards turbine.
The unwanted impurities (e.g. fish, plastics etc.) present in the
stored water are avoided to flow towards turbine.
Spill way:
The excess water from dam is discharges through spillway at a permissible level.
It is also known as safety valve of dam.
Surge tank:
A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of a sudden valve closure.
Surge tanks are usually provided in high or medium - head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock.
The main functions of the surge tank are:
1. When the load decreases, the water moves backwards and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank
Forebay:
Instead of surge tank some hydro-electric power plants used Forebay.
The Forebay are useful as the surge due to change in load occurs.
Forebay is an enlarged body of water at the intake (dam) to store more quantity of water.
It is nothing but regulating reservoir.
Forebay stores the rejected water as the load on the turbine decreases & supplies water immediately when load on turbine increases i.e. it is nothing but surge tank for small capacity hydro power station.
9. In hydro-electric power plants, ______ reduces water hammer effect in penstock
A. Spillway
B. Trash rack
C. Surge tank
D. Forebay
Answer: C. Surge tank
Explanation:
2. When the load increases, an additional supply of water will be provided by the surge tank.
10. Among the following which is/are the baseload power station/plant?
1) Hydroelectric
2) Biogas
3) Diesel
A. Only 1,2,3
B. Only 4
C. Only 4, 3
D. Only 1, 2
Answer: D. Only 1, 2
Explanation:
Baseload power station:
Explanation:
Surge tank:
A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of sudden valve closure.
It also acts as small storage from which water may be supplied in case of a sudden valve opening of the turbine. In case of a sudden opening of the turbine valve, there are chances of penstock collapse due to a negative pressure generation. If there is no surge tank.
Surge tanks are usually provided in high or medium - head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock. The main functions of the surge tank are:
1. When the load decreases, the water moves backwards and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank.
A. Pelton
B. Kaplan
C. Francis
D. Propeller
Answer: C. Francis
Explanation:
In Francis Turbine the medium head is required generally in the range of (30-500) meter. In Kaplan Turbine very low head is required, generally less than 30-meter
In Francis Turbine medium flow rate is required. In Kaplan Turbine very large flow rate is required
High head turbine:
In this type of turbine, the net head varies from 500m to 2000m or even more, and these turbines require a small quantity of water. Example: Pelton wheel turbine.
Medium head turbine:
The net head varies from 30m to 500m, and also these turbines require a moderate quantity of water. Example: Francis turbine.
Low head turbine:
The net head is less than 30m and also these turbines require a large quantity of water. Example: Kaplan turbine.
2. The surge tanks are usually provided in high or medium head _____ power plants when considerably _____ is required.
A. Hydro-electric, short penstock
B. Hydro-electric, long penstock
C. Thermal, short penstock
D. Thermal, large steam turbine
Answer: B. Hydro-electric, long penstock
2. The surge tanks are usually provided in high or medium head _____ power plants when considerably _____ is required.
A. Hydro-electric, short penstock
B. Hydro-electric, long penstock
C. Thermal, short penstock
D. Thermal, large steam turbine
Answer: B. Hydro-electric, long penstock
Explanation:
- Surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of sudden valve closure.
- The surge tank is located between the almost horizontal or slightly inclined conduit and steeply sloping penstock and is designed as a chamber excavated in the mountain
- It also acts as small storage from which water may be supplied in case of a sudden valve opening of the turbine.
- In case of a sudden opening of the turbine valve, there are chances of penstock collapse due to a negative pressure generation. If there is no surge tank.
- Surge tanks are usually provided in high or medium - head hydroelectric power plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock.
The main functions of the surge tank are:
1. When the load decreases, the water moves backward and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank.
3. The most efficient power plant is ______.
A. Hydroelectric power plant
B. Coal-based steam power plant
C. Nuclear power plant
D. Diesel engine power plant
Answer: A. Hydroelectric power plant
Explanation:
Power station VS Efficiency
- Steam Power station---25%
- Hydro Power station---85%
- Diesel Power station---35%
- Nuclear Power station---55%
Note:
- Hydro turbines, the oldest and the most commonly used renewable energy source, have the most efficient of all power conversion processes. The potential head of water is available right next to the turbine, so there are no energy conversion losses, only the mechanical and copper losses in the turbine and generator and the tail end loss. The efficiency is in the range of 85 to 90 %.
- Wind turbines have an overall conversion efficiency of 30 % to 45 %. These two renewable sources, though efficient, are dependent on the availability of the energy source.
- Solar thermal systems can achieve efficiency up to 20 %. The moving path of the sun and the weather conditions drastically alter the incident solar radiation. The efficiency on an annual basis, around 12 %, is considerably less than on a daily basis.
- Geothermal systems, on the other hand, also use the Rankine cycle with steam temperatures at a saturation point. Since there is no other conversion loss, this plant can achieve efficiencies in the range of 35 %.
4. Rammam hydroelectric power project is located in
A. Purulia
B. Bankura
C. Jalpaiguri
D. Darjeeling
Answer: D. Darjeeling
Explanation:
The correct answer is Darjeeling.
- Rammam hydroelectric power project is a run of the river-based hydel project.
- Rammam river flows through the Darjeeling district of West Bengal.
- It originates from the Singalila range in Darjeeling.
- The Lodhoma river is a tributary of the Rammam river.
- Ramman river merges with the Rangeet river near Jorethang at the end of its course.
- Run-of-the-river based hydroelectricity project is a method of hydroelectricity generation using natural flow and elevation drop of a river.
- This type of power station is successful for the river which has a consistent and steady flow.
- No reservoir is used to store water to move the turbine to convert mechanical energy into electricity.
5. The advantage of hydro-electric power station over thermal power station is:
A. The initial cost of hydro-electric power station is low
B. The operating cost of hydro-electric power station is low
C. Hydro-electric power station can supply the power throughout the year
D. Hydro-electric power station can be constructed at the place where the energy is required
Answer: B. The operating cost of hydro-electric power station is low
Explanation:
A generating station which utilises the potential energy of water at a high level for the generation of electrical energy is known as a hydro-electric power station.
Advantages:
- It requires no fuel as water is used for the generation of electrical energy.
- It is quite neat and clean as no smoke or ash is produced.
- It requires very small running charges because water is the source of energy which is available free of cost.
- It is comparatively simple in construction and requires less maintenance.
- It does not require a long starting time like a steam power station. In fact, such plants can be put into service instantly.
- It is robust and has a longer life.
- In addition to the generation of electrical energy, they also help in irrigation and controlling floods.
Disadvantages:
- It involves high capital cost due to construction of dam.
- There is uncertainty about the availability of huge amount of water due to dependence on weather conditions.
- Skilled and experienced hands are required to build the plant.
- It requires high cost of transmission lines as the plant is located in hilly areas which are quite away from the consumers.
6. The hydraulic turbine suitable for a speed range of 95 to 440 rpm is:
A. Pelton wheel
B. Kaplan
C. Rankine
D. Francis
Answer: D. Francis
Explanation:
The specific speed of a turbine is defined as, the speed of a geometrically similar Turbine that would develop unit power when working under a unit head (1m head).
Low specific speed turbine:
The specific speed is less than 60 rpm. (varying from 10 to 35 for single jet and up to 50 for a double jet) Example: Pelton wheel turbine
Medium-specific turbine:
The specific speed varies from 60 to 300 rpm. Example: Francis turbine
High specific turbine: the specific speed is more than 300 rpm. Example: Kaplan or propeller turbine
Reaction turbines are used for low and medium heads (usually less than 300 m) and for high discharge.
Flow VS Energy VS Head VS Specific speed VS Example
Tangential--Impulse--High head(300 m and above)--Low(0 – 60 RPM)--Pelton Wheel turbine
Radial--Reaction--Medium(30 m to 300 m)--Medium(60 – 300) RPM--Francis turbine
Axial--Reaction--Low(less than 30 m)--High(300 – 600) RPM--Propeller turbine(600 – 1000) RPM-Kaplan turbine
7. Which of the following scientific principles is mainly behind the generation of hydroelectric power?
A. Conversion of gravitational energy into electrical energy
B. Conversion of gravitational potential energy into thermal energy
C. Conversion of electrical energy into kinetic energy
D. Conversion of gravitational potential energy into electrical energy
Answer: D. Conversion of gravitational potential energy into electrical energy
Explanation:
The correct answer is the Conversion of gravitational potential energy into electrical energy.
Hydroelectric Power Plant:
- Hydroelectric power is produced by the gravity of falling water.
- In the hydroelectric power plant, more electrical power can be generated, if waterfalls from a greater height because the rise in water level causes the increase in potential energy of water.
- It flows from a higher position more amount of kinetic energy is formed by the conversion of higher potential energy and this kinetic energy in the form of moving water can produce more electrical power.
- The Koyna Hydroelectric Project is the largest completed hydroelectric plant in India. Its power capacity is 1920 megawatts.
- The first hydroelectric power station was the Shivanasamudra hydroelectric power station.
- Tehri Hydro Power Plant is the tallest hydropower project in the country, and Terry Dam is also the tallest hydropower plant in India.
- The Srisailam hydroelectric power station is the third-largest construction project in India.
- The Naspajakri Hydroelectric Power Plant is the largest underground hydroelectric project in the country.
- Bhakra Nangal Hydroelectric Power Plant Himachal Pradesh
- Tehri Hydro Electric Power plant Uttarakhand
- Hirakud Hydro Electric Power plant Odisha
- Nagarjunasagar Hydro-Electric Power Plant Andhra Pradesh
- Sardar Sarovar Hydro Electric Power plant Gujarat
- Koyna Hydroelectric Power plant Maharashtra
- Balimela Hydro Electric Power plant Odisha
8. Trash rack, forebay, surge tank, spill way are the terms involved with:
A. nuclear power plant
B. thermal power plant
C. wind turbine based power plant
D. hydroelectric power plant
Answer: D. hydroelectric power plant
Explanation:
Trash rack, forebay, surge tank, spill way are the terms involved with hydroelectric power plant.
Track Rask:
It is used in hydro-electric power plant to filter the water before it flows towards turbine.
The unwanted impurities (e.g. fish, plastics etc.) present in the
stored water are avoided to flow towards turbine.
Spill way:
The excess water from dam is discharges through spillway at a permissible level.
It is also known as safety valve of dam.
Surge tank:
A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of a sudden valve closure.
Surge tanks are usually provided in high or medium - head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock.
The main functions of the surge tank are:
1. When the load decreases, the water moves backwards and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank
Forebay:
Instead of surge tank some hydro-electric power plants used Forebay.
The Forebay are useful as the surge due to change in load occurs.
Forebay is an enlarged body of water at the intake (dam) to store more quantity of water.
It is nothing but regulating reservoir.
Forebay stores the rejected water as the load on the turbine decreases & supplies water immediately when load on turbine increases i.e. it is nothing but surge tank for small capacity hydro power station.
9. In hydro-electric power plants, ______ reduces water hammer effect in penstock
A. Spillway
B. Trash rack
C. Surge tank
D. Forebay
Answer: C. Surge tank
Explanation:
- When the water flowing in a long pipe is suddenly brought to rest by closing the valve or by any similar cause, there will be a sudden rise in pressure due to the momentum of the moving water being destroyed. This causes a wave of high pressure to be transmitted along the pipe which creates noise known as knocking. This phenomenon of the sudden rise in pressure in the pipe is known as water hammer or hammer blow.
- A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of sudden valve closure.
- It also acts as small storage from which water may be supplied in case of a sudden valve opening of the turbine. In case of a sudden opening of the turbine valve, there are chances of penstock collapse due to a negative pressure generation. If there is no surge tank.
- Surge tanks are usually provided in high or medium - head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock.
2. When the load increases, an additional supply of water will be provided by the surge tank.
10. Among the following which is/are the baseload power station/plant?
1) Hydroelectric
2) Biogas
3) Diesel
4) Pumped storage
A. Only 1,2,3
B. Only 4
C. Only 4, 3
D. Only 1, 2
Answer: D. Only 1, 2
Explanation:
Baseload power station:
Baseload is the minimum level of electricity demand required over a period of 24 hours. It is needed to provide power to components that keep running at all times (also referred to as continuous load). Plants that are running continuously over extended periods of time are said to be baseload power plants.
Example:
Nuclear power plant
Coal or thermal power plant
Hydroelectric plant
Geothermal plant
Biogas plant
Biomass plant
Solar thermal with storage
Ocean thermal energy conversion
Peak load power station:
Example:
Nuclear power plant
Coal or thermal power plant
Hydroelectric plant
Geothermal plant
Biogas plant
Biomass plant
Solar thermal with storage
Ocean thermal energy conversion
Peak load power station:
Peak load is the time of high demand. These peaking demands are often for only shorter durations. To cater to the demand peaks, peak load power plants are used. They are started up whenever there is a spike in demand and stopped when the demand recedes.
Example:
Gas plant
Solar power plants
Wind turbines
Pumped storage plants
Diesel generatorsSo, the solar power plant is different from other power plants.
11. Whenever closed conduits are used in a hydroelectric power plant, __________ is/are used to limit the abnormal pressure in the conduit.
A. penstocks
B. surge tank
C. headworks
D. spilways
Answer: B. surge tank
Example:
Gas plant
Solar power plants
Wind turbines
Pumped storage plants
Diesel generatorsSo, the solar power plant is different from other power plants.
11. Whenever closed conduits are used in a hydroelectric power plant, __________ is/are used to limit the abnormal pressure in the conduit.
A. penstocks
B. surge tank
C. headworks
D. spilways
Answer: B. surge tank
Explanation:
Surge tank:
A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of sudden valve closure.
It also acts as small storage from which water may be supplied in case of a sudden valve opening of the turbine. In case of a sudden opening of the turbine valve, there are chances of penstock collapse due to a negative pressure generation. If there is no surge tank.
Surge tanks are usually provided in high or medium - head plants when there is a considerable distance between the water source and the power unit, necessitating a long penstock. The main functions of the surge tank are:
1. When the load decreases, the water moves backwards and gets stored in it.
2. When the load increases, an additional supply of water will be provided by the surge tank.