Memory in which data accessing has to follow a sequence: ?->(Show Answer!)

1. Memory in which data accessing has to follow a sequence:

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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->Memory in which data accessing has to follow a sequence:....

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MCQ-> Directions : In the following questions, you have two brief passages with 5 questions in each passage, Read the passages carefully and choose the best answer to each question out of the four alternatives. PASSAGE -I Stuck with be development dilemma? Stay away from management courses. Seriously, one of the biggest complaints that organisations have about management courses is that they fail to impact the participants' on-the-job behaviour. Some management trainers stress the need for follow-up and reinforcement on the job. Some go so far as briefing the participants' managers on what behaviour they should be reinforcing back on the job. Others include a follow-up training day to review the progress of the participants. None of this is really going far enough. The real problem is that course promoters view development as something which primarily, takes place in a classroom. A course is an event and events are, by definition limited in time. When you talk about follow-up after a course, it is seen as a nice idea, but not as an essential part of the participants' development programme. Any rational, empowered individual should be able to take what has been learnt in a course and transfer it to the work place or so the argument goes. Another negative aspect of the course mindset is that, primarily, development is thought to be about skill-acquisition. So, it is felt that the distinction between taking the course and behaving differently in the work place parallels the distinction between skill-acquisition and skill-application. But can such a sharp distinction be maintained ? Skills are really acquired only in the context of applying them on the job, finding them effective and therefore, reinforcing them. The problem with courses is that they are events, while development is an on-going process which, involves, within a complex environment, continual interaction, regular feedback and adjustment. As we tend to equate development with a one-off event, it is difficult to get seriously motivated about the follow-up. Anyone paying for a course tends to look at follow-up as an unnecessary and rather costly frill. PASSAGE II One may look at life, events, society, history, in another way. A way which might, at a stretch, be described as the Gandhian way, though it may be from times before Mahatma Gandhi came on the scene. The Gandhian reaction to all the grim poverty, squalor and degradation of the human being would approximate to effort at self-change and self-improvement, to a regime of living regulated by discipline from within. To change society, the individual must first change himself. In this way of looking at life and society, words too begin to mean differently. Revolution, for instance, is a term frequently used, but not always in the sense it has been in the lexicon of the militant. So also with words like peace and struggle. Even society may mean differently, being some kind of organic entity for the militant, and more or less a sum of individuals for the Gandhian. There is yet another way, which might, for want of a better description, be called the mystic. The mystic's perspective measures these concerns that transcend political ambition and the dynamism of the reformer, whether he be militant or Gandhian. The mystic measures the terror of not knowing the remorseless march of time:he seeks to know what was before birth, what comes after death. The continuous presence of death, of the consciousness of death, sets his priorities. and values: militants and Gandhians kings and prophets must leave all that they have built:all that they have un-built and depart when messengers of the buffalo-riding Yama come out of the shadows. Water will to water, dust to dust. Think of impermanence. Everything passes.What is the passage about?
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MCQ-> These questions consist of a question and two statements numbered I and H given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and mark the appropriate answer. Give answer : Topic:banking-reasoning-data-sufficiency a: The data even in both statements I and II together are not sufficient to answer the question. b: The data in statement I alone are sufficient to answer the question while the data in statement II alone are not sufficient to answer the question. c: The data either in statement I alone or in statement II alone are sufficient to answer the question. d: The data in both statements I and II together are necessary to answer the question. e: The data in statement II alone are sufficient to answer the question while the data in statement I are not sufficient to answer the question.In a building, the ground floor is numbered one, first floor is numbered two and so on till the topmost floor is numbered five. Amongst five people- M, N, O, P and Q, each living on a different floor, but not necessarily in the same order, on which floor does Q live ? I. O lives on an odd numbered floor. M lives immediately below O. Only two people live between M and P. N lives neither immediately below M nor immediately below P. II. N lives on an even numbered floor. Only two people live between N and O. Only one person lives between O and Q.....