These 25 MCQs cover various aspects of Power Plant Engineering, including the types and functions of different power plants, components and systems used in power generation, and operational principles. They are designed to test knowledge in both theoretical and practical contexts in the field of Mechanical Engineering.
1. What is the primary function of a power plant?
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Explanation:
The primary function of a power plant is to convert thermal energy, often produced by burning fossil fuels or through nuclear reactions, into electrical energy for distribution and consumption.
2. What type of power plant uses the energy of flowing water to generate electricity?
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Explanation:
Hydroelectric power plants use the energy of flowing or falling water to drive turbines, which in turn generate electricity. They are a significant source of renewable energy.
3. What is the role of a boiler in a thermal power plant?
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Explanation:
In a thermal power plant, the boiler's primary role is to convert water into steam by heating it. This steam is then used to drive turbines and generate electricity.
4. What principle does a nuclear power plant operate on?
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Explanation:
Nuclear power plants generate electricity through nuclear fission reactions, where the nucleus of an atom splits into smaller parts, releasing a significant amount of energy used to produce steam and drive turbines.
5. What is a cooling tower used for in a power plant?
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Explanation:
Cooling towers in power plants are used to remove excess heat from the cooling water that has been used to condense the steam back into water in the plant's condenser.
6. In a coal-fired power plant, what is the function of the pulverizer?
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Explanation:
The pulverizer in a coal-fired power plant grinds the coal into a fine powder. This increases the surface area of the coal, allowing it to burn more efficiently in the boiler.
7. What is the purpose of a condenser in a steam power plant?
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Explanation:
The condenser in a steam power plant condenses the exhaust steam from the turbine back into water. This water is then reused in the boiler, making the process more efficient.
8. What type of power plant uses geothermal energy to generate electricity?
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Explanation:
Geothermal power plants use the Earth's heat (geothermal energy) to generate electricity. They harness steam or hot water from underground reservoirs to drive turbines for power generation.
9. What is combined cycle power generation?
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Explanation:
Combined cycle power generation involves using both a gas turbine and a steam turbine in tandem. The waste heat from the gas turbine is used to generate steam, which then drives a steam turbine, enhancing overall efficiency.
10. What is the function of the superheater in a steam power plant?
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Explanation:
A superheater in a steam power plant increases the temperature of the steam above its saturation point without increasing its pressure. This superheated steam has higher thermal efficiency and reduces moisture content during the expansion in turbines.
11. What is cogeneration?
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Cogeneration, also known as combined heat and power (CHP), is the simultaneous production of electricity and useful heat from the same energy source. It is a highly efficient use of fuel or energy source.
12. What is the Rankine cycle in power plant engineering?
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Explanation:
The Rankine cycle is a thermodynamic cycle that converts heat into work, primarily used in steam power plants. It is the fundamental operating cycle of all thermal power plants where an operating fluid is continuously evaporated and condensed.
13. What is the main advantage of using a gas turbine for power generation?
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Gas turbines have the advantage of quick start-up and shutdown times compared to other types of power plants. This makes them suitable for meeting peak demands and emergency power supply.
14. In a nuclear reactor, what material is commonly used as a moderator?
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In many nuclear reactors, graphite is used as a moderator to slow down the speed of neutrons. Slower neutrons are more likely to cause fission in the fuel (such as uranium), maintaining the chain reaction.
15. What is the primary use of a wind turbine?
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Wind turbines are used to convert the kinetic energy of wind into mechanical energy, which can then be used directly for mechanical work or converted into electrical energy.
16. What is the purpose of the spillway in a hydroelectric power plant?
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Explanation:
The spillway in a hydroelectric power plant is used to control the water level in the reservoir. It provides a route for water to pass safely over or around a dam without damaging the power plant structure.
17. What is the primary environmental concern with coal-fired power plants?
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Explanation:
Coal-fired power plants are a major source of air pollution and greenhouse gas emissions, primarily due to the burning of coal, which releases pollutants like sulfur dioxide, nitrogen oxides, particulate matter, and carbon dioxide.
18. In a power plant, what is the function of a deaerator?
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Explanation:
A deaerator is used in a power plant to remove dissolved gases, particularly oxygen and carbon dioxide, from the boiler feedwater. This prevents corrosion and improves the efficiency and longevity of the steam system.
19. What is the principle of operation of a solar thermal power plant?
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Explanation:
Solar thermal power plants use solar energy to heat a fluid, typically water or a heat-transfer fluid, to generate steam. This steam then drives a turbine to produce electricity.
20. In a tidal power plant, what is the primary source of energy?
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Explanation:
Tidal power plants harness the energy from the rise and fall of tides, which are caused by the gravitational pull of the moon and sun. This movement of water is used to drive turbines and generate electricity.
21. What is 'load shedding' in the context of power plant operation?
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Explanation:
Load shedding is a measure taken to avoid overloading the power plant or grid. It involves cutting off the electricity supply to certain areas or sectors to balance the demand with the available supply and prevent a total blackout.
22. What is a binary cycle power plant?
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Explanation:
A binary cycle power plant is a type of geothermal power plant that uses two different fluids: geothermal water to heat a secondary working fluid (like isobutane) which then vaporizes and drives a turbine to generate electricity.
23. In a power plant, what is the purpose of a flue gas desulfurization unit?
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Explanation:
A flue gas desulfurization unit is used in power plants to remove sulfur dioxide and other sulfur compounds from the exhaust flue gas. This process helps reduce air pollution and environmental impact, particularly from coal-fired power plants.
24. What is the advantage of a pumped-storage hydroelectric power plant?
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Explanation:
Pumped-storage hydroelectric power plants can store energy by pumping water to a higher elevation during periods of low demand. During periods of high energy demand, the stored water is released back down to drive turbines and generate electricity.
25. What is the significance of the 'heat rate' in a power plant?
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Explanation:
The heat rate in a power plant is a measure of its efficiency, expressed as the amount of fuel required to produce one unit of electricity. A lower heat rate indicates a more efficient power plant as it uses less fuel to generate the same amount of electricity.