Q11. Which of the following is a disadvantage of nuclear fission as an energy source?
a) Minimal environmental impact
b) Generation of long-lived radioactive waste
c) Abundance of fuel resources
d) Low risk of accidents
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Correct Answer: b) Generation of long-lived radioactive waste
Explanation: One of the disadvantages of nuclear fission as an energy source is the generation of long-lived radioactive waste, including spent nuclear fuel and other byproducts of nuclear reactions. Proper management and disposal of radioactive waste present significant challenges due to its potential environmental and health hazards.
Q12. What is the primary purpose of nuclear fusion reactions?
a) To generate electricity in nuclear power plants
b) To produce nuclear weapons
c) To replicate the energy source of the Sun and stars
d) To induce radioactive decay
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Correct Answer: c) To replicate the energy source of the Sun and stars
Explanation: Nuclear fusion reactions aim to replicate the energy-producing process that powers the Sun and other stars. By fusing light nuclei such as hydrogen isotopes together to form heavier elements, nuclear fusion releases vast amounts of energy. Efforts to harness controlled fusion for practical energy production are ongoing but present significant technical challenges.
Q13. Which of the following elements is commonly used as a fuel in nuclear fusion reactions?
a) Uranium
b) Hydrogen
c) Plutonium
d) Thorium
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Correct Answer: b) Hydrogen
Explanation: Hydrogen, particularly isotopes such as deuterium and tritium, is commonly used as fuel in nuclear fusion reactions. Deuterium is abundant in water, while tritium can be produced from lithium, making hydrogen-based fusion a potentially sustainable and abundant energy source.
Q14. What is the role of confinement methods in nuclear fusion experiments?
a) To initiate nuclear reactions
b) To absorb excess neutrons
c) To prevent heat loss from the fusion plasma
d) To shield the surrounding environment from radiation
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Correct Answer: c) To prevent heat loss from the fusion plasma
Explanation: Confinement methods in nuclear fusion experiments are designed to contain and stabilize the high-temperature plasma where fusion reactions occur. By preventing heat loss from the fusion plasma, confinement methods help maintain the conditions necessary for sustained nuclear fusion reactions and energy production.
Q15. Which of the following is a major challenge in achieving controlled nuclear fusion for practical energy production?
a) Limited availability of fusion fuels
b) Generation of radioactive waste
c) Difficulty in initiating nuclear reactions
d) Confinement of the high-temperature plasma
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Correct Answer: d) Confinement of the high-temperature plasma
Explanation: One of the major challenges in achieving controlled nuclear fusion for practical energy production is effectively confining the high-temperature plasma where fusion reactions occur. Maintaining the conditions necessary for sustained fusion reactions, including high temperatures and pressures, while preventing plasma instabilities and heat loss poses significant technical challenges.
Q16. Which of the following confinement methods involves using powerful magnetic fields to contain and stabilize the fusion plasma?
a) Inertial confinement
b) Magnetic confinement
c) Gravitational confinement
d) Electrostatic confinement
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Correct Answer: b) Magnetic confinement
Explanation: Magnetic confinement is a technique used in fusion research to contain and stabilize the high-temperature plasma where fusion reactions occur. Powerful magnetic fields are generated and shaped to confine the plasma within a defined region, preventing it from contacting the walls of the fusion reactor and losing heat.
Q17. What is the primary fusion reaction that powers the Sun?
a) Deuterium-tritium fusion
b) Proton-proton fusion
c) Carbon-oxygen fusion
d) Helium-helium fusion
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Correct Answer: b) Proton-proton fusion
Explanation: The primary fusion reaction that powers the Sun is proton-proton fusion, also known as the proton-proton chain reaction. In this process, hydrogen nuclei (protons) fuse together to form helium nuclei, releasing energy in the form of gamma rays and neutrinos.
Q18. Which of the following is a potential advantage of nuclear fusion compared to nuclear fission for energy production?
a) Generation of long-lived radioactive waste
b) Abundance of fuel resources
c) Minimal risk of accidents
d) Requirement for critical mass
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Correct Answer: b) Abundance of fuel resources
Explanation: Nuclear fusion has the potential advantage of utilizing abundant fuel resources, particularly isotopes of hydrogen such as deuterium and lithium. Deuterium can be extracted from water, while lithium is found in various minerals. Unlike uranium, which is finite and requires enrichment, fusion fuel resources are virtually limitless.
Q19. What is the temperature required to initiate nuclear fusion reactions?
a) Hundreds of degrees Celsius
b) Thousands of degrees Celsius
c) Tens of thousands of degrees Celsius
d) Millions of degrees Celsius
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Correct Answer: d) Millions of degrees Celsius
Explanation: Nuclear fusion reactions require extremely high temperatures to overcome the electrostatic repulsion between positively charged atomic nuclei and bring them close enough for the strong nuclear force to bind them together. Temperatures on the order of millions of degrees Celsius are necessary to achieve the conditions for sustained fusion reactions.
Q20. Which of the following fusion reactions is considered the most promising for practical energy production?
a) Deuterium-tritium fusion
b) Deuterium-deuterium fusion
c) Tritium-tritium fusion
d) Proton-boron fusion
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Correct Answer: a) Deuterium-tritium fusion
Explanation: Deuterium-tritium fusion is considered the most promising fusion reaction for practical energy production in the near term. It has the highest fusion cross-section and the lowest energy threshold among fusion reactions involving light nuclei, making it the most feasible reaction to achieve ignition and sustainment in fusion reactors.