Which one of the following phrases best describes residual magnetism? ?->(Show Answer!)

1. Which one of the following phrases best describes residual magnetism?

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MCQ-> In the following questions, two columns are given containing three sentences/phrases each. In the first column, sentences/phrases are A, B and C and in the second column, the sentences/phrases are D, E and F. A sentence/phrase from the first column may or may not connect with another sentence/phrase from the second column to make a grammatically and contextually correct sentence. Each question has five options, four of which display the sequence(s) in which the sentences/phrases can be joined to form a grammatically and contextually correct sentence. Select the option that contains the correct sequence in which the phrases can be joined together to form a grammatically correct sentence. If none of the options given forms a correct sentence after combination, mark (e), i.e.“None of these” as your answer and if all the options given form a correct sentence, mark ‘All of these’ as your answer.

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MCQ-> Read the following passage carefully and answer the questions given below it. Certain words/phrases have been printed in bold to help you locate them while answering some of the questions. The past quarter of a century has seen several bursts of selling by the world’s governments, mostly but not always in benign market conditions. Those in the OECD, a rich-country club, divested plenty of stuff in the 20 years before the global financial crisis. The first privatisation wave, which built up from the mid-1980s and peaked in 2000, was largely European. The drive to cut state intervention under Margaret Thatcher in Britain soon spread to the continent. The movement gathered pace after 1991, when eastern Europe put thousands of rusting state-owned enterprises (SOEs) on the block. A second wave came in the mid-2000s, as European economies sought to cash in on buoyant markets. But activity in OECD countries slowed sharply as the financial crisis began. In fact, it reversed. Bailouts of failing banks and companies have contributed to a dramatic increase in government purchases of corporate equity during the past five years. A more lasting fea ture is the expansion of the state capitalism practised by China and other emerging economic powers. Governments have actually bought more equity than they have sold in most years since 2007, though sales far exceeded purchases in 2013. Today privatisation is once again “alive and well”, says William Megginson of the Michael Price College of Business at the University of Oklahoma. According to a global tally he recently completed, 2012 was the third-best year ever, and preliminary evidence suggests that 2013 may have been better. However, the geography of sell-offs has changed, with emerging markets now to the fore. China, for instance, has been selling minority stakes in banking, energy, engineering and broadcasting; Brazil is selling airports to help finance a $20 billion investment programme. Eleven of the 20 largest IPOs between 2005 and 2013 were sales of minority stakes by SOEs, mostly in developing countries. By contrast, state-owned assets are now “the forgotten side of the balance-sheet” in many advanced economies, says Dag Detter, managing partner of Whetstone Solutions, an adviser to governments on asset restructuring. They shouldn’t be. Governments of OECD countries still oversee vast piles of assets, from banks and utilities to buildings, land and the riches beneath (see table). Selling some of these holdings could work wonders: reduce debt, finance infrastructure, boost economic efficiency. But governments often barely grasp the value locked up in them. The picture is clearest for companies or company-like entities held by central governments. According to data compiled by the OECD and published on its website, its 34 member countries had 2,111 fully or majority-owned SOEs, with 5.9m employees, at the end of 2012. Their combined value (allowing for some but not all pension-fund liabilities) is estimated at $2.2 trillion, roughly the same size as the global hedge-fund industry. Most are in network industries such as telecoms, electricity and transport. In addition, many countries have large minority stakes in listed firms. Those in which they hold a stake of between 10% and 50% have a combined market value of $890 billion and employ 2.9m people. The data are far from perfect. The quality of reporting varies widely, as do definitions of what counts as a state-owned company: most include only centralgovernment holdings. If all assets held at sub-national level, such as local water companies, were included, the total value could be more than $4 trillion. Reckons Hans Christiansen, an OECD economist. Moreover, his team has had to extrapolate because some QECD members, including America and Japan, provide patchy data. America is apparently so queasy about discussions of public ownership of -commercial assets that the Treasury takes no part in the OECD’s working group on the issue, even though it has vast holdings, from Amtrak and the 520,000-employee Postal Service to power generators and airports. The club’s efforts to calculate the value that SOEs add to, or subtract from, economies were abandoned after several countries, including America, refused to co-operate. Privatisation has begun picking up again recently in the OECD for a variety of reasons. Britain’s Conservative-led coalition is fbcused on (some would say obsessed with) reducing the public debt-to-GDP ratio. Having recently sold the Royal Mail through a public offering, it is hoping to offload other assets, including its stake in URENCO, a uranium enricher, and its student-loan portfolio. From January 8th, under a new Treasury scheme, members of the public and businesses will be allowed to buy government land and buildings on the open market. A website will shortly be set up to help potential buyers see which bits of the government’s /..337 billion-worth of holdings ($527 billion at today’s rate, accounting for 40% of developable sites round Britain) might be surplus. The government, said the chief treasury secretary, Danny Alexander, “should not act as some kind of compulsive hoarder”. Japan has different reasons to revive sell-offs, such as to finance reconstruction after its devastating earthquake and tsunami in 2011. Eyes are once again turning to Japan Post, a giant postal-to-financial-services conglomerate whose oftpostponed partial sale could at last happen in 2015 and raise (Yen) 4 trillion ($40 billion) or more. Australia wants to sell financial, postal and aviation assets to offset the fall in revenues caused by the commodities slowdown. In almost all the countries of Europe, privatisation is likely “to surprise on the upside” as long as markets continue to mend, reckons Mr Megginson. Mr Christiansen expects to see three main areas of activity in coming years. First will be the resumption of partial sell-offs in industries such as telecoms, transport and utilities. Many residual stakes in partly privatised firms could be sold down further. France, for instance, still has hefty stakes in GDF SUEZ, Renault, Thales and Orange. The government of Francois Hollande may be ideologically opposed to privatisation, but it is hoping to reduce industrial stakes to raise funds for livelier sectors, such as broadband and health. The second area of growth should be in eastern Europe, where hundreds of large firms, including manufacturers, remain in state hands. Poland will sell down its stakes in listed firms to make up for an expected reduction in EU structural funds. And the third area is the reprivatisation of financial institutions rescued during the crisis. This process is under way: the largest privatisation in 2012 was the $18 billion offering of America’s residual stake in AIG, an insurance company.Which of the following statements is not true in the context of the given passage ?
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MCQ-> In a modern computer, electronic and magnetic storage technologies play complementary roles. Electronic memory chips are fast but volatile (their contents are lost when the computer is unplugged). Magnetic tapes and hard disks are slower, but have the advantage that they are non-volatile, so that they can be used to store software and documents even when the power is off.In laboratories around the world, however, researchers are hoping to achieve the best of both worlds. They are trying to build magnetic memory chips that could be used in place of today’s electronics. These magnetic memories would be nonvolatile; but they would also he faster, would consume less power, and would be able to stand up to hazardous environments more easily. Such chips would have obvious applications in storage cards for digital cameras and music- players; they would enable handheld and laptop computers to boot up more quickly and to operate for longer; they would allow desktop computers to run faster; they would doubtless have military and space-faring advantages too. But although the theory behind them looks solid, there are tricky practical problems and need to be overcome.Two different approaches, based on different magnetic phenomena, are being pursued. The first, being investigated by Gary Prinz and his colleagues at the Naval Research Laboratory (NRL) in Washington, D.c), exploits the fact that the electrical resistance of some materials changes in the presence of magnetic field— a phenomenon known as magneto- resistance. For some multi-layered materials this effect is particularly powerful and is, accordingly, called “giant” magneto-resistance (GMR). Since 1997, the exploitation of GMR has made cheap multi-gigabyte hard disks commonplace. The magnetic orientations of the magnetised spots on the surface of a spinning disk are detected by measuring the changes they induce in the resistance of a tiny sensor. This technique is so sensitive that it means the spots can be made smaller and packed closer together than was previously possible, thus increasing the capacity and reducing the size and cost of a disk drive. Dr. Prinz and his colleagues are now exploiting the same phenomenon on the surface of memory chips, rather spinning disks. In a conventional memory chip, each binary digit (bit) of data is represented using a capacitor-reservoir of electrical charge that is either empty or fill -to represent a zero or a one. In the NRL’s magnetic design, by contrast, each bit is stored in a magnetic element in the form of a vertical pillar of magnetisable material. A matrix of wires passing above and below the elements allows each to be magnetised, either clockwise or anti-clockwise, to represent zero or one. Another set of wires allows current to pass through any particular element. By measuring an element’s resistance you can determine its magnetic orientation, and hence whether it is storing a zero or a one. Since the elements retain their magnetic orientation even when the power is off, the result is non-volatile memory. Unlike the elements of an electronic memory, a magnetic memory’s elements are not easily disrupted by radiation. And compared with electronic memories, whose capacitors need constant topping up, magnetic memories are simpler and consume less power. The NRL researchers plan to commercialise their device through a company called Non-V olatile Electronics, which recently began work on the necessary processing and fabrication techniques. But it will be some years before the first chips roll off the production line.Most attention in the field in focused on an alternative approach based on magnetic tunnel-junctions (MTJs), which are being investigated by researchers at chipmakers such as IBM, Motorola, Siemens and Hewlett-Packard. IBM’s research team, led by Stuart Parkin, has already created a 500-element working prototype that operates at 20 times the speed of conventional memory chips and consumes 1% of the power. Each element consists of a sandwich of two layers of magnetisable material separated by a barrier of aluminium oxide just four or five atoms thick. The polarisation of lower magnetisable layer is fixed in one direction, but that of the upper layer can be set (again, by passing a current through a matrix of control wires) either to the left or to the right, to store a zero or a one. The polarisations of the two layers are then either the same or opposite directions.Although the aluminum-oxide barrier is an electrical insulator, it is so thin that electrons are able to jump across it via a quantum-mechanical effect called tunnelling. It turns out that such tunnelling is easier when the two magnetic layers are polarised in the same direction than when they are polarised in opposite directions. So, by measuring the current that flows through the sandwich, it is possible to determine the alignment of the topmost layer, and hence whether it is storing a zero or a one.To build a full-scale memory chip based on MTJs is, however, no easy matter. According to Paulo Freitas, an expert on chip manufacturing at the Technical University of Lisbon, magnetic memory elements will have to become far smaller and more reliable than current prototypes if they are to compete with electronic memory. At the same time, they will have to be sensitive enough to respond when the appropriate wires in the control matrix are switched on, but not so sensitive that they respond when a neighbouring elements is changed. Despite these difficulties, the general consensus is that MTJs are the more promising ideas. Dr. Parkin says his group evaluated the GMR approach and decided not to pursue it, despite the fact that IBM pioneered GMR in hard disks. Dr. Prinz, however, contends that his plan will eventually offer higher storage densities and lower production costs.Not content with shaking up the multi-billion-dollar market for computer memory, some researchers have even more ambitious plans for magnetic computing. In a paper published last month in Science, Russell Cowburn and Mark Well and of Cambridge University outlined research that could form the basis of a magnetic microprocessor — a chip capable of manipulating (rather than merely storing) information magnetically. In place of conducting wires, a magnetic processor would have rows of magnetic dots, each of which could be polarised in one of two directions. Individual bits of information would travel down the rows as magnetic pulses, changing the orientation of the dots as they went. Dr. Cowbum and Dr. Welland have demonstrated how a logic gate (the basic element of a microprocessor) could work in such a scheme. In their experiment, they fed a signal in at one end of the chain of dots and used a second signal to control whether it propagated along the chain.It is, admittedly, a long way from a single logic gate to a full microprocessor, but this was true also when the transistor was first invented. Dr. Cowburn, who is now searching for backers to help commercialise the technology, says he believes it will be at least ten years before the first magnetic microprocessor is constructed. But other researchers in the field agree that such a chip, is the next logical step. Dr. Prinz says that once magnetic memory is sorted out “the target is to go after the logic circuits.” Whether all-magnetic computers will ever be able to compete with other contenders that are jostling to knock electronics off its perch — such as optical, biological and quantum computing — remains to be seen. Dr. Cowburn suggests that the future lies with hybrid machines that use different technologies. But computing with magnetism evidently has an attraction all its own.In developing magnetic memory chips to replace the electronic ones, two alternative research paths are being pursued. These are approaches based on:
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MCQ-> Read the passage carefully and answer the given questionsThe complexity of modern problems often precludes any one person from fully understanding them. Factors contributing to rising obesity levels, for example, include transportation systems and infrastructure, media, convenience foods, changing social norms, human biology and psychological factors. . . . The multidimensional or layered character of complex problems also undermines the principle of meritocracy: the idea that the ‘best person’ should be hired. There is no best person. When putting together an oncological research team, a biotech company such as Gilead or Genentech would not construct a multiple-choice test and hire the top scorers, or hire people whose resumes score highest according to some performance criteria. Instead, they would seek diversity. They would build a team of people who bring diverse knowledge bases, tools and analytic skills. . . .Believers in a meritocracy might grant that teams ought to be diverse but then argue that meritocratic principles should apply within each category. Thus the team should consist of the ‘best’ mathematicians, the ‘best’ oncologists, and the ‘best’ biostatisticians from within the pool. That position suffers from a similar flaw. Even with a knowledge domain, no test or criteria applied to individuals will produce the best team. Each of these domains possesses such depth and breadth, that no test can exist. Consider the field of neuroscience. Upwards of 50,000 papers were published last year covering various techniques, domains of enquiry and levels of analysis, ranging from molecules and synapses up through networks of neurons. Given that complexity, any attempt to rank a collection of neuroscientists from best to worst, as if they were competitors in the 50-metre butterfly, must fail. What could be true is that given a specific task and the composition of a particular team, one scientist would be more likely to contribute than another. Optimal hiring depends on context. Optimal teams will be diverse.Evidence for this claim can be seen in the way that papers and patents that combine diverse ideas tend to rank as high-impact. It can also be found in the structure of the so-called random decision forest, a state-of-the-art machine-learning algorithm. Random forests consist of ensembles of decision trees. If classifying pictures, each tree makes a vote: is that a picture of a fox or a dog? A weighted majority rules. Random forests can serve many ends. They can identify bank fraud and diseases, recommend ceiling fans and predict online dating behaviour. When building a forest, you do not select the best trees as they tend to make similar classifications. You want diversity. Programmers achieve that diversity by training each tree on different data, a technique known as bagging. They also boost the forest ‘cognitively’ by training trees on the hardest cases - those that the current forest gets wrong. This ensures even more diversity and accurate forests.Yet the fallacy of meritocracy persists. Corporations, non-profits, governments, universities and even preschools test, score and hire the ‘best’. This all but guarantees not creating the best team. Ranking people by common criteria produces homogeneity. . . . That’s not likely to lead to breakthroughs.Which of the following conditions, if true, would invalidate the passage’s main argument?
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