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Department of Electrical and Electronics Engineering Editorial Board Members: C. Harinatha Reddy M.tech (PhD) Associate Professor M.Raviteja IV EEE (07891A0234) VMS.Pavan Kumar IV EEE (07891A0252) T.Sai Rahul IV EEE (07891A0238). Preface
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Department of Electrical and Electronics Engineering Editorial Board Members: C. Harinatha Reddy M.tech (PhD) Associate Professor M.Raviteja IV EEE (07891A0234) VMS.Pavan Kumar IV EEE (07891A0252) T.Sai Rahul IV EEE (07891A0238)
Preface It gives us a great pleasure to release the Second edition of the departmental magazine. The magazine’s members have shown considerable cooperation as well as devotion. As a part of the Departmental activities, EEE dept. has begun to publish the departmental magazine for each semester. It helps the reader to acquire information related to different areas of technology and current affairs too. Being a combination of technical and general topics, this magazine proves to be one of the best informative books. This magazine covers the upcoming technologies and also the market trends. On behalf of the magazine’s members; I would like to express our thanks to the teachers and students who have partially contributed to the magazine. We would also be pleased to receive any suggestion that could assist us with the third edition.
Who invented the CD player? James T Russell invented the CD, recorder and player in the 1960s with patents filed in 1971. Licenses issued to Phillips and Sony for development and production. Problem solving Questions A supermarket sells 500g pots of yoghourt. There is a special offer on yoghourt: Buy 2 pots and get a 3rd one free! A week later, the price of a single pot of yoghourt is still the same, but the offer changes to: Buy 1 pot and get a 2nd one for half price! Is the second offer better than the first?
Working of a Tube light: Tube light has a circuits one with choke (Inductor) and other with starter. Starter is a bimetallic strip current first pass through a circuit with filaments& heat the filaments just to start ionization of gas in the tube. Now the starter having basically bimetallic strip will heat up and current passes across this newly created joint to heat the filaments. The circuit is designed such that after some time starter will cut off and current suddenly becomes zero now here get some concept of an inductor. Inductor has a property that if current changes to zero i.e increase or decrease then this change will cause a high voltage to develop by Lenz law/or law of electromagnetic induction. We need this heavy voltage of 20000v so that the gas molecules in tube light & across filaments ionize & break and current which flows through this alternate circuit having choke, is able to flow through them emitting photons of light or plasma. Where did this heavy voltage came from? Right its the choke. A choke is a self inductor. Now starter may cause strips to join and then cool again , that is cut off again and again to cause ballasts of high voltage to break across gas molecules and emit plasma light. Then what a capacitor is doing here well it is there to improve power factor. Once tube light starts there is no role of starter circuit. Hence if u remove starter also when tube light is on it doesn’t matter.
Why SKY IS BULE? You may already know that sunlight is made up of all the colors of the rainbow: red, orange, yellow, green, blue, and violet. You probably also know that sunlight has to pass through our atmosphere before it reaches our eyes. The gas molecules in the atmosphere break up, or "scatter," the sunlight into its many parts. But they scatter some parts more effectively than others. Different colors of light have different energies, or wavelengths. Red light has a long wavelength and a lower energy; blue light has a short wavelength and a higher energy. The gas molecules in the atmosphere scatter the higher-energy blue wavelengths better than the red wavelengths. So the sky looks blue.
Threesquare • A piece of wire is 60cm long. • It is bent into a shape that consists of three • identical squares. How long is the side of a square? • Crazy Offers: • SEEKING CANDIDATES WITH A WIDE VARIETY OF EXPERIENCE: You'll need it to replace three people who just left. • MUST BE DEADLINE ORIENTED:You'll be six months behind schedule on your first day. • GOOD COMMUNICATION SKILLS:Management communicates, you listen, figure out what they want you to do. CAUGHT SLEEPING - TOP EXCUSES 1. They told me at the blood bank this might happen. 2. I wasn't sleeping! I was meditating on the mission statement and envisioning a new paradigm! 3. This is one of the seven habits of highly effective people 4. Actually I'm doing a "Stress Level Elimination Exercise Plan" (SLEEP). I learned it at the last mandatory seminar you made me attend. 5. I was doing a highly specific Yoga exercise to relieve work related stress. 6. Darn! Why did you interrupt me? I had almost figured out a solution to the maths problem. 7. Boy, that cold medicine I took last night just won't wear off! 8. I wasn't sleeping, I was trying to pick up contact lens without hands. 9. Amen.
Innovator: Phil Denby A British scientist thinks he can make solar cells that could power entire buildings out of particles too small to be seen without an electron microscope. Phil Denby almost talked himself out of his big idea for very small solar cells—so small they could be turned into a transparent spray that could be applied to windows the way tint is applied to car windshields and sunglasses. The 32-year-old Yorkshire-born Brit was doing postdoctoral research in Bergen, Norway, when he revisited a notion he'd been mulling for years—that metal nanoparticles, bits of matter thousands of times smaller than the width of a human hair, could be used to create a thin solar film. "If it was a good idea, someone would have done it before me," Denby says of his thinking at the time. A colleague encouraged Denby to pursue it anyway, and now his five-person, Bergen-based development shop, EnSol, has a patent pending for the spray. At 250 nanometers, EnSol's solar film is 800 times thinner than the silicon wafers that are used to make traditional solar cells, and dozens of times thinner than other solar films on the market. Using standard industrial coating techniques, EnSol's product could be applied to almost any surface, from windows to roof tiles—potentially turning whole buildings into solar panels. The cells could be manipulated to appear in any color. Denby won't say which metals EnSol uses, only that he says they are cheap and nontoxic. With an initial grant of about $75,000 from the Research Council of Norway, Denby recruited Chris Binns, a nanotech specialist at the University of Leicester in Britain, to help produce sample cells. So far the two have been able to make only a few square centimeters of film at a time. "We've got this stuff, we shine light on it, and it produces a current," says Binns. The next step is to test the film's efficiency, the rate at which it captures sunlight. Commercial silicon cells average around 15 percent efficiency; EnSol is aiming for 20 percent and hopes to have a product ready for the market by 2016. Robert W. Birkmire, director of the Institute of Energy Conversion at the University of Delaware, says that may be a challenge. "To actually make something that's marketable is a long road to hell," he says. Denby, now in talks with venture-capital firms, is making no guarantees. "It's very early in the day to say anything definite," he says. Denby wants to be sure investors are willing to stick with his idea. "It could be huge," he says. "I'm sort of a naïve scientist and would like to see a better world for everybody."
Who invented the Induction motor? We generally credit Nikola Tesla, the Serbian-American inventor, with the pioneering work of identifying the rotating magnetic induction field idea and applying it to a device that generated torque - rotational energy or force. His work on this occurred in about 1882. Thus the induction motor originated. DIFFERENCES BETWEEN YOU AND YOUR BOSS When you don't do it, you're lazy. When your boss doesn't do it, he's too busy. When you make a mistake, you're an idiot. When your boss makes a mistake, he's only human. When you're on a day off sick, you're always sick.When your boss has a day off sick, he must be very ill. THINK DIFFERENT
In Any interview, always handle the questions with confidence. Your competence in an interview with difficult questions will show that you are a potential employee who shines during stressful situations. Three, four, five (a) Find a multiple of 3, greater than 100, that is also a multiple of 4 (b) Give a number greater than 5 that is a multiple of 5 but is not a multiple of 2 or a multiple of 3 Terms A digital counter is set to count up in tens starting from 100, once a second. 100, 110, 120, 130 ... I00 Another digital counter is set to count down in tens starting from 1000 once a Second. 1000, 990, 980, 970 ... I000 Both counters start at exactly the same time. (a) After how many seconds do they each display the same number? (b) What number is this?
TOP TEN LEADERSHIP QUALITIES Leadership can be defined as one's ability to get others to willingly follow. Every organization needs leaders at every level. Leaders can be found and nurtured if you look for the following character traits. Integrity is the integration of outward actions and inner values. A person of integrity is the same on the outside and on the inside. Such an individual can be trusted because he or she never veers from inner values, even when it might be expeditious to do so. A leader must have the trust of followers and therefore must display integrity. Dedication means spending whatever time or energy is necessary to accomplish the task at hand. A leader inspires dedication by example, doing whatever it takes to complete the next step toward the vision. By setting an excellent example, leaders can show followers that there are no nine-to-five jobs on the team, only opportunities to achieve something great. Magnanimity means giving credit where it is due. A magnanimous leader ensures that credit for successes is spread as widely as possible throughout the company. Conversely, a good leader takes personal responsibility for failures. This sort of reverse magnanimity helps other people feel good about themselves and draws the team closer together. To spread the fame and take the blame is a hallmark of effective leadership
Leaders with humility recognize that they are no better or worse than other members of the team. A humble leader is not self-effacing but rather tries to elevate everyone. Leaders with humility also understand that their status does not make them a god. Mahatma Gandhi is a role model for Indian Openness means being able to listen to new ideas, even if they do not conform to the usual way of thinking. Good leaders are able to suspend judgment while listening to others’ ideas, as well as accept new ways of doing things that someone else thought of. Openness builds mutual respect and trust between leaders and followers, and it also keeps the team well supplied with new ideas that can further its vision. Creativity is the ability to think differently, to get outside of the box that constrains solutions. Creativity gives leaders the ability to see things that others have not seen and thus lead followers in new directions. The most important question that a leader can ask is, “What if … ?” Possibly the worst thing a leader can say is, “I know this is a dumb question ... ”
Fairness means dealing with others consistently and justly. A leader must check all the facts and hear everyone out before passing judgment. He or she must avoid leaping to conclusions based on incomplete evidence. When people feel they that are being treated fairly, they reward a leader with loyalty and dedication. Assertiveness is not the same as aggressiveness. Rather, it is the ability to clearly state what one expects so that there will be no misunderstandings. A leader must be assertive to get the desired results. Along with assertiveness comes the responsibility to clearly understand what followers expect from their leader. A sense of humor is vital to relieve tension and boredom, as well as to defuse hostility. Effective leaders know how to use humor to energize followers. Humor is a form of power that provides some control over the work environment. And simply put, humor fosters good camaraderie.
A leader with vision has a clear, vivid picture of where to go, as well as a firm grasp on what success looks like and how to achieve it. But it’s not enough to have a vision; leaders must also share it and act upon it. Jack Welch, former chairman and CEO of General Electric Co., said, "Good business leaders create a vision, articulate the vision, passionately own the vision and relentlessly drive it to completion." Put the numbers in Write four different numbers in the spaces to make the number sentence correct. ( – ) – ( – ) = 35 Write the following four numbers in the spaces to make this number sentence correct. 80 60 50 20 ( – ) – ( – ) = 10 AQA GCSE Problem-Solving Questions, 2008 - Additional Mathematics 64
Working of a Air Conditioner: Air conditioners and refrigerators work the same way. Instead of cooling just the small, insulated space inside of a refrigerator, an air conditioner cools a room, a whole house, or an entire business. Air conditioners use chemicals that easily convert from a gas to a liquid and back again. This chemical is used to transfer heat from the air inside of a home to the outside air. The machine has three main parts. They are a compressor, a condenser and an evaporator. The compressor and condenser are usually located on the outside air portion of the air conditioner. The evaporator is located on the inside the house, sometimes as part of a furnace. That's the part that heats your house. The working fluid arrives at the compressor as a cool, low-pressure gas. The compressor squeezes the fluid. This packs the molecule of the fluid closer together. The closer the molecules are together, the higher its energy and its temperature. The working fluid leaves the compressor as a hot, high pressure gas and flows into the condenser. If you looked at the air conditioner part outside a house, look for the part that has metal fins all around. The fins act just like a radiator in a car and helps the heat go away, or dissipate, more quickly. When the working fluid leaves the condenser, its temperature is much cooler and it has changed from a gas to a liquid under high pressure. The liquid goes into the evaporator through a very tiny, narrow hole. On the other side, the liquid's pressure drops. When it does it begins to evaporate into a gas. As the liquid changes to gas and evaporates, it extracts heat from the air around it. The heat in the air is needed to separate the molecules of the fluid from a liquid to a gas. The evaporator also has metal fins to help in exchange the thermal energy with the surrounding air. By the time the working fluid leaves the evaporator, it is a cool, low pressure gas. It then returns to the compressor to begin its trip all over again. Connected to the evaporator is a fan that circulates the air inside the house to blow across the evaporator fins. Hot air is lighter than cold air, so the hot air in the room rises to the top of a room. There is a vent there where air is sucked into the air conditioner and goes down ducts. The hot air is used to cool the gas in the evaporator. As the heat is removed from the air, the air is cooled. It is then blown into the house through other ducts usually at the floor level. This continues over and over and over until the room reaches the temperature you want the room cooled to. The thermostat senses that the temperature has reached the right setting and turns off the air conditioner. As the room warms up, the thermostat turns the air conditioner back on until the room reaches the temperature
New process that harnesses heat energy could double efficiency of solar cells • Photovoltaic solar cells convert light energy from the sun into electricity. Although significant strides have been made in increasing the efficiency of photovoltaic technology, they usually only result in incremental increases. Researchers at Stanford University have come up with a way that could more than double the efficiency of existing solar cell technology and potentially reduce the costs of solar energy production enough for it to compete with oil as an energy source. Instead of relying solely on photons, the new process, called “photon enhanced thermionic emission,” or PETE, simultaneously combines the light and heat of solar radiation to generate electricity. • Unlike photovoltaic technology currently used in solar panels – which becomes less efficient as the temperature rises – the new process excels at higher temperatures. The Stanford engineers who discovered it say the process promises to surpass the efficiency of existing photovoltaic and thermal conversion technologies. And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable. • Most photovoltaic cells, such as those used in rooftop solar panels, use the semiconducting material silicon to convert the energy from photons of light to electricity. But the cells can only use a portion of the light spectrum, with the rest just generating heat. This heat from unused sunlight and inefficiencies in the cells themselves account for a loss of more than 50 percent of the initial solar energy reaching the cell.
Capturing heat energy • The researchers knew that if this wasted heat energy could somehow be harvested, solar cells could be much more efficient. The problem has been that high temperatures are necessary to power heat-based conversion systems, yet solar cell efficiency rapidly decreases at higher temperatures. Until now, no one had come up with a way to wed thermal and solar cell conversion technologies. • Melosh's group figured out that by coating a piece of semiconducting material with a thin layer of the metal cesium, it made the material able to use both light and heat to generate electricity. • Solar farms • Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C. Dishes are used in large solar farms similar to those proposed for the Mojave Desert in Southern California and usually include a thermal conversion mechanism as part of their design, which offers another opportunity for PETE to help generate electricity as well as minimize costs by meshing with existing technology. • Efficiency rates of up to 60 percent • Photovoltaic systems never get hot enough for their waste heat to be useful in thermal energy conversion, but the high temperatures at which PETE performs are perfect for generating usable high-temperature waste heat. Melosh calculates the PETE process can get to 50 percent efficiency or more under solar concentration, but if combined with a thermal conversion cycle, could reach 55 or even 60 percent – almost triple the efficiency of existing systems. The team would like to design the devices so they could be easily bolted on to existing systems, thereby making • Proof of concept • The researchers used a gallium nitride semiconductor in the "proof of concept" tests. The efficiency they achieved in their testing was well below what they have calculated PETE's potential efficiency to be – which they had anticipated. But they used gallium nitride because it was the only material that had shown indications of being able to withstand the high temperature range they were interested in and still have the PETE process occur. • With the right material – most likely a semiconductor such as gallium arsenide, which is used in a host of common household electronics – the actual efficiency of the process could reach up to the 50 or 60 percent the researchers have calculated. They are already exploring other materials that might work.
Another advantage of the PETE system is that by using it in solar concentrators, the amount of semiconductor material needed for a device is quite small conversion relatively inexpensive. • The cost of materials has been one of the limiting factors in the development of the solar power industry, so reducing the amount of investment capital needed to build a solar farm is a big advance. • "The PETE process could really give the feasibility of solar power a big boost," Melosh said. "Even if we don't achieve perfect efficiency, let's say we give a 10 percent boost to the efficiency of solar conversion, going from 20 percent efficiency to 30 percent, that is still a 50 percent increase overall." • And the researchers say that is still a big enough increase that it could make solar energy competitive with oil. Sevendiff Three whole numbers have a total of 100 Two of the numbers have a difference of 7 Two of the numbers are the same. Find the numbers. Rollover Three circles overlap each other as shown in the diagram. The centres of the circles are all on the same straight line. A is the centre of the largest circle. B is the centre of the middle-sized circle. C is the centre of the smallest circle. The diameters of the circles are 22cm, 16cm and 13cm. Calculate the lengths BA and AC. B A C Not drawn to scale
Solar Tsunami • While almost everyone knows about the Tsunami, that refers to destructive waves of the sea. The news of solar Tsunami reading towards earth has left the world jittery of the relatively new and unknown phenomenon. • Sometimes you really can believe your eyes. That’s what NASA’s solar terrestrial relations observatory (STEREO) is telling researchers about a controversial phenomenon on the Sun known as the Solar Tsunami. • The satellites recorded a dark arc, identified as a large filament a cool gas stretching across the sun’s northern hemisphere as exploded into space. This explosion, called a coronal mass ejection, was aimed directly towards earth which then sent a Solar Tsunami racing 93 million miles across space. • However, there is nothing to worry about as the consequences and effects of solar tsunami would just be limited to blackouts, disruption in communication systems and a rather desirable effect of brighter auroras on the northern lights. • Scientists have assured that the tsunami posses no direct threat to earth and life on the planet, besides they are rejoicing the fact that this tsunami will help them to study the phenomenon better. • Facts: • Solar Tsunami is like shock wave that forms on the sun. • These waves generally roll across the hot surface of the sun destroying or sweeping away filamentary material. • These waves are infrequent yet very powerful. • Technical name “Fast mode Magneto Hydro Dynamical wave”.
Scientists hope to collect electricity from the air • Nikola Tesla once dreamed of being able to harness electricity from the air. Now, research being conducted at Brazil’s University of Campinas (UC) is indicating that such a scenario may indeed become a reality. Professor Fernando Galembeck, a UC chemist, is leading the study into the ways in which electricity builds up and spreads in the atmosphere, and how it could be collected. “Our research could pave the way for turning electricity from the atmosphere into an alternative energy source for the future," he stated. "Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect.” • Scientists once believed that water droplets in the atmosphere were electrically neutral, even after having come into contact with charged dust particles. Galembeck and his UC team, however, have shown that this isn’t the case. In a lab experiment, they noted that tiny particles of silica and aluminum phosphate became negatively and positively charged (respectively) when circulated in highly-humid air. “This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with,” Galembeck explained. “We are calling this 'hygroelectricity,' meaning 'humidity electricity'.” • He now pictures collectors, not unlike solar cells, that could someday collect and distribute hygroelectricity from the air. Just as solar cells work best in sunny places, his collectors would do best in humid parts of the world. He even believes it’s possible that by diminishing the electrical charge in the air, his collectors could prevent lightning, especially if mounted on top of tall buildings. His team is currently experimenting with different metals, to find out which would work best for capturing atmospheric electricity and preventing lightning strikes. • "These are fascinating ideas that new studies by ourselves and by other scientific teams suggest are now possible," he said. "We certainly have a long way to go. But the benefits in the long range of harnessing hygroelectricity could be substantial."
The age of a boy is 15 years.what is the age of his father.(think logically about the posible anwer) What is the next number in the series? ? 126 161 63 71 79 25 29 33 37 8 10 12 14 16 1 2 3 4 5 6 Moussey Here is a recipe for chocolate mousse. Chocolate Mousse 100g of chocolate 10g of butter 2 eggs This makes enough chocolate mousse for two people. I have 8 eggs, 45g of butter and 350g of chocolate. What is the maximum number of people I can make chocolate mousse for?