The Exciting World of Magnets: From Surgery to Space
Ans)
1.C. The mining process required for obtaining rare earth elements
Explanation: The text highlights the environmental concerns associated with mining for rare earth elements, which are crucial for making powerful magnets.
2.B. A device that aids in hearing
Explanation: Cochlear implants are mentioned in the context of using magnets to assist with hearing, indicating they are devices designed to improve hearing capabilities.
3.C. No error
Explanation: The sentence is grammatically correct as written, with appropriate use of a comma before the relative clause and correct subject-verb agreement.
4.C. Electric cars
Explanation: The article discusses how stronger magnets can make electric cars run more efficiently and weigh less, making them the most directly benefited technology mentioned.
5.B. Trees are to reforestation
Explanation: Just as reforesting involves planting trees to replenish the environment, recycling magnets involves processing used magnets to reduce environmental impact.
6.C. iron and nitrogen
Explanation: The article mentions that some companies are developing magnets using iron and nitrogen, avoiding the use of rare earth elements.
7.A. Remove
Explanation: "Extract" in the context of the article refers to the removal of rare earth elements from the ground through mining, similar to the general meaning of remove.
8.B. Inefficient
Explanation: The antonym of "efficient" is "inefficient," meaning not performing in the best possible manner with the least waste of time and effort.
9.B. It highlights the global dependency on China for magnets.
Explanation: The article emphasizes the significant market share China holds in magnet production, highlighting a dependency that affects global magnet supply.
10.C. To reduce reliance on rare earth elements
Explanation: Using iron and nitrogen aims to reduce the environmental and economic impacts associated with mining rare earth elements.
11.A. Decreased need for mining
Explanation: Advancements in magnet recycling reduce the need to mine new materials, lessening environmental impact and reliance on new rare earth element extraction.
12.C. They will become more efficient and lighter.
Explanation: The article discusses how stronger magnets contribute to more efficient and lighter electric cars, suggesting improvements in vehicle performance and design.
13.C. They reduce the weight of devices like electric cars.
Explanation: The article points out that stronger magnets can make devices like electric cars lighter, which is a significant benefit.
14.B. Iron nitride
Explanation: Iron nitride is mentioned as an alternative material being used to create magnets that do not require rare earth elements.
15.C. To perform surgeries without large incisions
Explanation: The article describes how magnets are used in surgeries to manipulate instruments within the body without making large incisions, making the procedures less invasive.
16.B. To improve the environmental impact of magnet production
Explanation: The emphasis on developing new types of magnets is primarily to reduce the environmental harm caused by traditional magnet production methods, which involve mining for rare earth elements.
Writing Example
Essay
In recent years, the global demand for magnets, especially those used in high-tech applications such as electric vehicles and renewable energy systems, has surged significantly. However, the dominance of China in the production of these essential components has raised concerns about supply security and technological independence worldwide. This essay will discuss the implications of this reliance and propose measures to mitigate its effects.
China's control over magnet production, particularly those made from rare earth elements, accounts for more than 90% of the global market. This monopoly poses significant risks, including potential supply shortages and price manipulations, which can hinder technological advancements in other countries. For instance, in sectors like renewable energy and automotive manufacturing, where efficient and powerful magnets are crucial, dependency on a single supplier can lead to vulnerabilities in the event of political tensions or export restrictions.
Moreover, this centralization discourages innovation outside China. Countries dependent on imports for critical materials are often reluctant to invest in research and development of alternative technologies, fearing the unpredictability of supply chains. This scenario stifles global innovation and keeps potential technological breakthroughs tethered to the policies and economic objectives of one nation.
To address these challenges, countries should take a two-pronged approach: diversifying sources of magnet supply and investing in alternative technologies. Diversification can be achieved by developing magnet production capabilities domestically or in collaboration with allies. This not only secures a more stable supply but also fosters economic growth and job creation within domestic industries.
Furthermore, investing in research for alternative magnet technologies that do not require rare earth elements could reduce environmental impacts and dependence on problematic supply chains. Innovations such as iron nitride magnets, which offer similar properties to their rare earth counterparts, could provide a sustainable and less geopolitically fraught alternative.
In conclusion, while China’s dominance in magnet production has fueled global technological advancements, it has also created significant vulnerabilities. By diversifying supply sources and investing in new technologies, the world can mitigate these risks and foster a more stable and innovative technological landscape.
(311 words)
Short writing
1.Answer: Magnets are used in surgical devices to perform minimally invasive operations, in electric vehicles to improve efficiency and reduce weight, and in wind turbines to help generate renewable energy.
2.Answer: Developing new methods is important to reduce the environmental damage caused by mining rare earth elements, which are typically used in the production of powerful magnets.
3.Answer: Recycling old magnets helps to minimize environmental degradation, reduces the need for new mining operations, and supports the sustainable use of resources.
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