Which of the following is false about disk when compared to main memory? ?->(Show Answer!)

1. Which of the following is false about disk when compared to main memory?

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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->Study the given information carefully and answer the given question. Following are the observations of an experiment on 'sleep and memory' conducted on 18 healthy young adults (ages 18 to 25) and 18 healthy older adults (ages 61 to 81). A. The recall after 8 hours of sleep in younger adults was 65% more than that in the older adults. B. Night-sleep had higher negative impact on all of the participants as compared to that of daysleep of equal duration. C. If a given set' of words is memorised immediately before going to sleep, its recall after waking up was found to be better in younger adults than in the older adults. Which of the following can be concluded from the given findings of the research ? I. As per the experiment, there is some correlation between sleep and memory. II. The part of brain involved in memory is more active during the day as compared to that during the night. III. A sleep of more than 8 hours can improve the memory in older adults. IV. Memorising something immediately after waking up from an 8-hour long sleep will yield better results than memorising before sleep.....

MCQ-> Analyse the following passage and provide appropriate answers for the follow. Popper claimed, scientific beliefs are universal in character, and have to be so if they are to serve us in explanation and prediction. For the universality of a scientific belief implies that, no matter how many instances we have found positive, there will always be an indefinite number of unexamined instances which may or may not also be positive. We have no good reason for supposing that any of these unexamined instances will be positive, or will be negative, so we must refrain from drawing any conclusions. On the other hand, a single negative instance is sufficient to prove that the belief is false, for such an instance is logically incompatible with the universal truth of the belief. Provided, therefore, that the instance is accepted as negative we must conclude that the scientific belief is false. In short, we can sometimes deduce that a universal scientific belief is false but we can never induce that a universal scientific belief is true. It is sometimes argued that this 'asymmetry' between verification and falsification is not nearly as pronounced as Popper declared it to be. Thus, there is no inconsistency in holding that a universal scientific belief is false despite any number of positive instances; and there is no inconsistency either in holding that a universal scientific belief is true despite the evidence of a negative instance. For the belief that an instance is negative is itself a scientific belief and may be falsified by experimental evidence which we accept and which is inconsistent with it. When, for example, we draw a right-angled triangle on the surface of a sphere using parts of three great circles for its sides, and discover that for this triangle Pythagoras' Theorem does not hold, we may decide that this apparently negative instance is not really negative because it is not a genuine instance at all. Triangles drawn on the surfaces of spheres are not the sort of triangles which fall within the scope of Pythagoras' Theorem. Falsification, that is to say, is no more capable of yielding conclusive rejections of scientific belief than verification is of yielding conclusive acceptances of scientific beliefs. The asymmetry between falsification and verification, therefore, has less logical significance than Popper supposed. We should, though, resist this reasoning. Falsifications may not be conclusive, for the acceptances on which rejections are based are always provisional acceptances. But, nevertheless, it remains the case that, in falsification, if we accept falsifying claims then, to remain consistent, we must reject falsified claims. On the other hand, although verifications are also not conclusive, our acceptance or rejection of verifying instances has no implications concerning the acceptance or rejection of verified claims. Falsifying claims sometimes give us a good reason for rejecting a scientific belief, namely when the claims are accepted. But verifying claims, even when accepted, give us no good and appropriate reason for accepting any scientific belief, because any such reason would have to be inductive to be appropriate and there are no good inductive reasons.According to Popper, the statement "Scientific beliefs are universal in character" implies that....

MCQ-> Below is given a passage followed by several possible inferences which can be drawn from the facts stated in the passage You have to examine each inference separately in the context of the passage and decide upon its degree of truth or falsity Give answer a:if the inference is “definitely true” i.e it properly follows from the statement of facts given Give answer b:if the inference is ‘ probably true’ though not ‘ definitely true’ in the light of the facts given Give answer c:if the data are inadequate i.e from the facts given you cannot say whether the inference is likely to be true or false Give answer d:if the inference is “probably false” though not “definitely false” in the light of the facts given e:if the inference is “definitely false” i.e it cannot possibly be drawn from the facts given or it contradicts the given facts. With the purpose of upliftment of Gonda district in Uttar Pradesh a new formula was evolved for practical success in several fields such as irrigation animal husbandry dairy farming moral uplift and creation of financial resources Small farms were clustered for irrigation by one diesel pump which could irrigate about 20 acres of land Youth were prompted to take loans from the banks for purchase of engine pumps to be supplied to the farmers on rent This formula worked so well that the villages in Gonda district were saturated with irrigation facilities. Cattle rearing was linked with multiple cropping Most of the targets fixed for different areas were achieved which was an unusual phenomenon This could be possible only because of right motivation participation and initiative of the people Imagination and creativity combined together helped in finding out workable solutions to the problems of the community.There was no problem and complaint of the people residing in entire Gonda district before the beginning of the project
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MCQ-> Read the following passage carefully and answer the questions based on it. Some words have been printed in bold to help you locate them while answering some of the questions.Notwithstanding the fact that the share of household savings to GDS is showing decline, still this segment is the significant contributor to GDS with 70% share. Indian households are among the most frugal in the world However, commensurate capital formation has not been taking place as a lion's share of household savings are being parked in physical assets compared to financial assets. The pattern of disposition of saving is an important factor in determining how the saved amount is utilized for productive purposes. The proportion of household saving in financial assets determines the channelisation of saving for investment in other sectors of the economy. However, the volume of investment of saving in physical assets determines the productivity and generation of income in that sector itself. Post-Independence era has witnessed a significant shift in deployment of household savings especially the share of financial assets increased from 26.39% in 1950 to 54.05% in 1990 may be on account of increased bank branch network across the country coupled with improved awareness of investors on various financial / banking products. However, contrast to common expectations, the share of financial assets in total household savings has come down from 54.05% to 50.21% especially in post reform period i.e. 1990 to 2010 despite providing easy access and availability of banking facilities compared to earlier years. The increased share of physical assets over financial assets (around 4%) during the last two decades is a cause of concern requires focused attention to arrest the trend. Traditionally, the Indians are risk-averse and prefer to invest surplus funds in physical assets such as Gold, Silver and lands. Nevertheless, considerable share of savings also owing to financial assets, which includes, Currency, Bank Deposits, Claims on Government, Contractual Savings, Equities The composition of household financial savings shows that the bank deposits (44%) continue to remain the major contributor along with the rise in the Contractual Savings, Claims on Government and Currency. Though there was gradual decline in currency holdings by the households i.e. 13.79% in 1970s to 9.30% in 2007, still the present currency holding level with households appears to be on high side compared to other countries. The primary reasons for higher currency holdings could be absence of banking facilities in majority villages (5.70 lakh villages)as well as hoarding of unaccounted money in the form of cash to circumvent tax laws. Though, cash is treated as financial asset, in reality, a major portion of currency is blocked and become unproductive. Bank deposits seemed to be the preferred choice mainly on account of its inbuilt features such as Safety, Security and Liquidity. Traditionally, the Household sector has been playing a leading role in the landscape of bank deposits followed by the Government sector. However, the last two decades has witnessed significant shift in ownership of Bank deposits. While there was improvement in Corporate and Government sectors' share by 8.30% and 7.20% respectively during the period 1999 to 2009, household sector lost a share of 13.30% in the post reform period. In the post independence era, Indian financial system was characterized by poor infrastructure and low level of financial deepening. Savings in physical assets constituted the largest portion of the savings compared to the financial assets in the initial years of the planning periods. While rural households were keen on acquiring farm assets, the portfolio of urban households constituted consumer durables, gold, jewellery and house property.Despite the fact that the household savings have been gradually moving from physical assets to financial assets over the years, still 49.79% of household savings are wrapped in unproductive physical assets, which is a cause of concern as the share of physical assets to total savings are very high in the recent years compared to emerging economies. This trend needs to be arrested as scarce funds are being diverted into unproductive segments. Of course, investment in Real estate sector can be treated as productive provided construction activity is commenced within reasonable time, but it is regrettably note that many investors just buy and hold it for speculation leading to unproductive investments. India has probably the largest fascination with gold than any other country in the world with a share of 9.50% of the world's total gold holdings. The World Gold Council believes that they are over 18000 tonnes of gold holding in the country. More impressive is the fact that current demand from India alone consumes 25% of the world's annual gold output. Large amount of capital is blocked in gold which resides in bank lockers and remain unproductive. Indian economy would grow faster if the capital markets could attract more of the nation's savings and channel them into more productive areas, especially infrastructure. If the Indian market can develop and evolve into a more mature financial system, which persuades the middle class to put more of its money into equities, the potential is mind-boggling.Which of the following statement (s) is/are correct in the context of the given passage? I. The GDS percentage to GDP has shown considerable improvement from 10% in 1950 to 33.7% in 2010, which is one of the highest globally. II. The saving rate however shows an increasing trend, marginal decline is observed under tic use hold sector. III. The share of financial assets in total household savings have come down from 54.05% to 21% especially in post reform era.....