Fields are said to be circularly polarised if their magnitudes are ?->(Show Answer!)

1. Fields are said to be circularly polarised if their magnitudes are

Write Comment

Comments

Tags

Show Similar Question And Answers

QA->The Appalachian coal fields; one of the important coal fields in the world; are located in which country?....

QA->The Appalachian coal fields, one of the important coal fields in the world, are located in which country?....

QA->Indiajointly agreed with which country to maintain the pace of their high-levelexchanges in counter- terrorism and other fields?....

QA->Who said "Well done is better than well said”?....

QA->‘our education has got to be revolutionized. The brain must be educated through hands. Those who do not train hands, and go through the ordinary suit of education, lack music in their life’. Who said this ?....

MCQ-> Read the following passage carefully and answer the questions given below it. Certain word/phrases have been printed in bold to help you locate them while answering some of the questions.The men of Suvarnanagari were very lazy. They only liked to gossip and tell each other tall tales. As soon as the sun rose, the men would tuck into hearty breakfast and then gather in groups for their daily session of gossiping. Then they would spend the rest of the day telling each other impossible stories. They came back only at lunch and dinner time. The farmlands of Suvarnanagari were very fertile. If the men had spent even a little time at fields, they would have reaped wonderful crops. But as they did nothing, all the responsibilities ended up on shoulders of the woman. They had to work hard the whole day. They cooked, cleaned, sent the children to school, worked in the fields, took the crops to the market - in short they did everything. One day the tired woman gathered and decided that the men needed to be taught a lesson. One of them suggested that they should write to the king about their problem, as he was known to be just and a kind person. So the letter was written and sent to the king. The women went back to their daily routines, hoping that the king would soon take some action. Many days passed, nothing changed, no one came, and the poor women began to lose hope. ‘After all why would the king of such a vast empire be concerned about the plight of the women of such a tiny village?’ they thought. A month passed by and it was a full moon night. The men ate their dinners and because it was so beautiful and well lit outside, they gathered again to chat and boast. That night they were trying to prove to one another that they were capable of performing the most impossible tasks. Soon a tall and handsome stranger joined them. Seeing his noble features and intelligent eyes, each one wanted to prove himself better than the others and impress to him. One said, ‘’I knew the map of this kingdom even before I was born. I ran to meet the king as soon as I was born, my mother had such trouble bringing me back home !’’ Everyone was impressed by this story. Soon another man said, ‘’So what is so great about that ? When I was a just a day old, I could ride a horse. I sat on a big horse and rode all the way to the king’s palace. He received me with lot of love and we had the most delicious meal together.’’ This was even more impressive, so everyone applauded. Now the third man said, ‘’Huh! That is nothing. I sat on an elephant when I was a week old and had lunch with the king in his palace.’’Before the admiring murmurs could die down, the fourth man said, ‘’When I was a month old, I flew like a bird and landed in the king’s garden. The king picked me up and even let me sit on his throne with him,’’ While everyone was in awe of these stories, the stranger spoke up, ‘’ Do all four of you know the king very well?’’ ‘’Of course we do! ‘’ they replied together. ‘’Our king knows and love us. In fact, he is proud to have supernatural beings like us in his kingdom,’’ one of them added. The stranger looked thoughtful. ‘’That makes my task so much easier. You see, I work in the king’s court. Some days ago the king had summoned four supermen to the city in order to repair a large hole in the city wall. As you know, we use only the largest and toughest stones for building these walls, and they could be lifted and put in place only by these supermen. The four supermen asked to be paid in gold bars and the king complied.But the night they received their fee, they disappeared from the palace. I have been wandering around ever since looking for them. The king has ordered me to find the four men and bring them back to the capital to finish the work. They will also have to return the gold bars they ran away with. It looks like the search has finally ended. I will take the four of you to the king along with the gold bars. The king will be very pleased with me and will surely reward me,’’ said the stranger. By the time the stranger finished his story, the four men realised that their lies had landed them into a huge trouble. Their faces turned ashamed and they dived at the stranger’s feet. ‘’Those were all lies. We are all just a bunch of lazy men. But if you forgive us and forget our stories, we promise to do some honest work and stop telling such lies,’’ they wailed. The stranger smiled and said, ’’Alright, I will tell the king there are no supermen in this village, just honest and hardworking men and women.’’ That night the stranger left the village. The women were sure that it was none other than the king himself.How did the men of Suvarnanagiri spend their days ?
....

MCQ->Fields are said to be circularly polarised if their magnitudes are....

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:
....

MCQ-> Read the following passage carefully and answer the given questions. Certain words are given in bold to help you to locate them while answering some of the questions. King Harish loved his people and look after the affairs of the kingdom well. One day he and his minister Chandan took a stroll through the market. People were buying and selling and there were no beggars to be seen anywhere. The King was delighted to see the prosperity of his kingdom. He turned to Chandan and said, ‘I want to check firsthand how content my people are. Summon people from all walks of life to court.” The next day, ‘the king arrived at court and said, As your king I want to know if all of you are happy. Do you have enough for your needs?” The citizens looked at each other, thought and one by one came forward to say that their kitchens have enough food, their trade was going well, their wells were overflowing and the king had kept them safe. The king was pleased at this but Chandan had a frown and he whispered something to the king. The king was astonished but seeing Chandan was serious he turned to the court and made an announcement, “I am delighted you are all happy. Tomorrow I want all the happy people to gather at the gate of the royal garden. You have to enter the garden from the main gate, walk across and meet me by the gate at the rear of the garden. Each of you will be given a sack and you can pick whatever your heart desires.” The crowd was excited as no one was usually allowed access to the king’s garden which was said to be filled with all kinds of beautiful and strange plants.The next day, everyone gathered at the gate of the palace garden well before time. At the appointed time the guards opened the gates and handed out sacks. Citizens began roaming around the garden and filled their sacks with the juicy apples, pomegranates, grapes and mangoes hanging from trees. But as they walked further into the garden they saw trees laden with gold and silver fruits. They began madly filling their sacks with these precious fruits. Everyone forgot that they had enough for their needs at home and the fruits they had picked earlier were thrown on the ground forgotten and left to rot. Then with their sacks filled to the top the citizens made their way to the rear gate but they found a rushing stream blocking their path. The current was strong and as there were no boats, the only way to cross was to swim across. But how could they swim with laden sacks. All stood by the stream except one young man who simply abandoned his sack and swam across. Angry and unhappy the others refused to cross. The king was sad and said, “Yesterday all of you said you were happy but today you are distressed. ”Turning to the young man who was smiling he asked, ‘Tell me why are you not sad?” “Sire, I picked some tasty fruits for my precious daughter but when I saw no other way across, I did not think twice about leaving these behind. I am happy you let us wander around in your garden.”Choose the word which is most nearly the opposite in meaning to the word SERIOUS given in bold as used in the passage.
....

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. Once upon a time, there lived a lion in a forest. A jackal, a crow and a wolf had developed friendship. They knew that the lion was the king of the forest and friendship with such a fierce creature would always help them. To meet their selfish ends, they started obeying and were always at the service of the lion. They didn’t have to make any efforts to search for their food, as the lion gave his leftover meals to them. Moreover, they became powerful as they were next to the king of the forest. One day, a camel, who came from some distant land, lost his way and entered the same forest where these friends lived. In the meantime, these three friends happened to pass the same way that the camel was wandering. When they saw the camel, they realized that he did not belong to their forest. The jackal suggested to his other two friends, “Let’s kill and eat him.” The wolf replied, “It is a big animal. We cannot kill him like this. I think, we should first inform our king about this camel.” The crow agreed with the wolf s idea. All of them went to meet the lion. On reaching the lion’s den, the jackal approached the lion and said, Your Majesty, an unknown camel has dared to enter your kingdom without your consent, Let’s kill him; he could make a nice meal.” The lion roared loudly on hearing this and said, ‘What are you saying ? The camel has come for refuge in ray kingdom. It is unethical to kill him. We should provide him the best shelter. Go and bring him to me,” All of them were dispirited to hear these words from the king. They unwillingly went to the camel and told him about the lion’s desire to meet him, The camel was scared about the strange offer. He thought that his end had come and in a little while he would become the lion’s meal. As he couldn’t even escape, he decided to meet the lion. The selfish friends escorted the camel to the lion’s den. The lion welcomed the camel warmly and assured him of a safe stay in the forest. The camel was totally amazed to hear the lion’s words. He happily started living with the jackal, the crow and the wolf. One day, when the lion was hunting for food, he had a struggle with a mighty elephant. The lion was badly injured in the struggle and became incapable of hunting for his food. Thus the lion had to sustain without food for days. Due to this, his friends too had to go hungry for days as they totally depended on the lion’s kill for their food. But the camel was satisfied grazing around in the forest. All the three friends were worried and discussed the matter among them, As the jackal, the crow and the wolf had set their evil eyes on the camel, they met once again and devised a plan to kill the camel. They went to the camel and said, “Dear Friend, you know our king has not eaten anything for many days now. He is unable to hunt due to his wounds and sickness. Under such circumstances, it becomes our duty to sacrifice ourselves to save the life of our king. Come with us, we will offer our bodies as food for him.” The camel didn’t understand their plan, but innocently nodded in favour of it. All of them approached the lion’s den. First of all, the crow came forward and said, “Your Majesty, I can’t see you like this. So please eat me.” The lion replied, “I would prefer to die than to perform such a sinful deed.” Then, the jackal came forward and said, “Your Majesty, crow’s body is too small for your appetite. I offer myself to you, as it is my duty to save your life.” The lion politely rejected the offer. As per the plan, now it was the wolf’s turn to offer himself to the king. So, the wolf came forward and said, “Your Majesty, jackal is quite small to gratify your hunger. I offer myself for this kind job, Please, kill me and appease your hunger.” But the Lion didn’t kill any of them. The camel, who was watching the whole scene felt reassured of his safety and also decided to go forward and complete the formality. He marched forward and said, “Your Majesty, why don’t you kill me ? You are my friend. Please allow me to offer you my body.” The lion found the offer quite appropriate as the camel himself had offered his body for food. The lion attacked the camel at once, ripped open his body and lore him into pieces. The lion and his friends feasted on the poor camel for days together.‘Why could the lion not hunt anymore ?
....