...Introduction: Are Electromagnetic Fields a Risk for Human Health? Power lines allow the transmission of electricity. These exist all over the world, but are more predominant in some places, depending on the energy consumption. Although they all work for the same purpose, there are different types of power lines systems, and some have higher voltages than the others. Electromagnetic fields are created with the conduction of electricity, “because of the movement and existence of the charges. During the 1970’s, an examination was made on childhood leukemia and the results found a possible relationship between an increase in the disease and exposure to electromagnetic fields. From that moment on, many other studies attempted to show a link between electromagnetic fields and other diseases, which has caused major concern in many people. While some studies claim that there is a link between the two, some others demand that there is not enough proof to categorize electromagnetic fields as dangerous to human health. Even though exposure to electromagnetic fields has been labeled as a “human carcinogen,” most experts claim that there is not enough proof to make this claim and most studies show no relationship between these diseases and exposure to EMFs. Perhaps, some other factors should be considered when linking EMFs to developing certain diseases. Since our company was concerned about our customers’ anxiety, we decided to make a report on the subject. This report will...
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...heating methods, a torch or open flame is directly applied to the metal part. But with induction heating, heat is actually "induced" within the part itself by circulating electrical currents. Induction heating relies on the unique characteristics of radio frequency (RF) energy. Since heat is transferred to the product via electromagnetic waves, the part never comes into direct contact with any flame, the inductor itself does not get hot, and there is no product contamination Important factors to consider: Efficiency of an induction heating system depends upon some factors- 1. Metal or Plastic 2. Thick or thin 3. Resistivity- Quick heating when high amount of resistance and vice versa 4. Magnetic or non-magnetic MRI USES A MAGNETIC FIELD TO ORIENT THE POSITION OF CERTAIN NUCLEI IN THE BODY. THE PRIMARY NUCLEI USED FOR MRI IMAGING IS IN THE HYDROGEN ATOM CALLED THE PROTON. AS THE BODY IS MADE UP OF 75% OF WATER AND WATER IS 2 PARTS HYDROGEN. MAKING THR NUCLEUS OF THE HDROGEN ATOM, THE PROTON, THE MOST ABUNDANT IN THE BODY. A RADIOWAVE IS THEN USED TO EXCITE THE PROTON WHICH RESONATE AND ADMIT VARYING SIGNALS WICH A RECEIVED, DIGITIZED AND DISPLAYED AS IMAGES. DIFFERENT SIGNALS BY DIFFERENT BODY TISSUES ARE THEN USED TO DIFFERENTIATE INDIVIDUAL ANATOMY. WHEN A TISSUE IS DAMAGED ITS COMPOSITION CHANGES AND IT GIVES OFF AN UNCHARACTERISTIC SIGNAL. SO WHEN DISPLAYED, THAT DAMAGED TISSUE IS DISTINGUISHABLE FROM THE OTHER HEALTHY ISSUE. X-RAY MACHINES ...
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...Micheal Faraday: Father of modern Electricity Faraday was born on September 22, 1791, in Newington (today’s South London), England. His father, James Faraday, was a blacksmith of slender income and challenged health who, with his wife, Margaret, managed to raise a tight-knit family of three children. Faraday's father was of the Sandemanian faith, which Faraday was to adopt as a guiding force throughout his life. When Faraday turned 14, he was apprenticed to a book binder, and during this time, familiarized himself with the teachings of Isaac Watts, a cleric from the previous century. It was Watts's work, The Improvement of the Mind, that put Faraday on the road to self-improvement. In 1810, Faraday began attending meetings of the then recently formed City Philosophical Society, where he heard lectures on scientific subjects, of which chemistry and electricity held the most sway over his imagination. Faraday's relationship with Sir Humphry Davy began when Faraday attended a series of lectures by the famous scientist. Faraday was about to dedicate the rest of his life to bookbinding when, in what turned out to be a happy accident, Davy injured himself as a result of an experiment gone awry, and, in need of a secretary, hired Faraday. Faraday then gave Davy a copy of bound notes from Davy's lectures that Faraday had attended. Davy was impressed, and in 1813, when an assistant at the Royal Institution lost his job, Davy hired Faraday as his replacement. When Davy went abroad...
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...ON THE ELECTRODYNAMICS OF MOVING BODIES By A. EINSTEIN June 30, 1905 It is known that Maxwell’s electrodynamics—as usually understood at the present time—when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives rise—assuming equality of relative motion in the two cases discussed—to electric currents of the same path and intensity as those produced by the electric forces in the former case. Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relatively to the “light medium,” suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of...
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...to a 0.90 T uniform magnetic field? (b) What if the angle between the wire and field is 45.0°? [Answer: (a) 7.6 N m–1; (b) 5.3 N m–1] 2. A 1.5 m length of wire carrying 4.5 A of current is oriented horizontally. At that point on the Earth’s surface, the dip angle of the Earth’s magnetic field makes an angle of 38° to the wire. Estimate the magnitude of the magnetic force on the wire due to the Earth’s magnetic field of 5.5 × 10–5 T at this point. [Answer: 2.3 × 10–4 N] 3. A 5.0 MeV (kinetic energy) proton enters a 0.20 T magnetic field, in a plane perpendicular to the field. What is the radius of its path? [Answer: 1.6 m] 4. Determine the magnitude and direction of the force between two parallel wires 35 m long and 6.0 cm apart, each carrying 25 A in the same direction. [Answer: 7.3 × 10–2 N, attractive] 5. Calculate the force on an airplane which has acquired a net charge of 1550 µC and moves with a speed of 120 ms-1 perpendicular to the Earth’s magnetic field of 5.0 × 10–5 T. [Answer: 9.3 × 10–6 N] 6. Determine the magnetic field midway between two long straight wires 2.0 cm apart in terms of the current I in one when the other carries 15 A. Assume these currents are (a) in the same direction, and (b) in opposite directions. [Answer: (a) (2 × 10–5)(I – 15) T; (b) (2 × 10–5)(I + 15) T] 7. A circular coil of radius 2.0 cm has 100 turns. Its plane is kept in a vertical position and a small magnetic compass is placed at...
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...Magnetic Levitation Emerging Technologies By Nick Presson Introduction Magnetic levitation has been around for years, but with advances in technology it may become a part of everyday life. The main emphasis for magnetic levitation is for transportation. Magnetically levitated ground transportation, or “Maglev”, is an advanced mode of surface high speed transportation whereby a vehicle gliding above a guideway is suspended, guided, and propelled by magnetic forces. Can you imagine a train that that actually floats in air 4 to 6 inches in the air and travels up to 300 mph. This technology can reduce air and highway congestion, air pollution, and petroleum use. Traditional Systems The transportation system in the United States has been much admired around the world. Our extensive highway and air systems have facilitated business and leisure travel and contributed to a high quality of life for many Americans. In 1990, 429 million passengers traveled 342 billion passenger miles on commercial airlines. Americans traveled 2 trillion passenger miles my car, truck, bus, and public transit, and 6.1 billion passenger miles on Amtrak. As population have grown and shifted, however, the traditional systems have become stressed. Congestion on highways and at airports, especially since September 11, not only wastes time and fuel increases, but also constrains mobility to the extent that economic...
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... Alec Sim_____________________________________________ Role | I | DC | AD | RC | Q1 | Q2 | PI | PG | | | | | | | | | | | | | | | | | | | | | | | | | | | | I introduction DC data and calculation AD analysis and discussion RC results and conclusion Q1/Q2 quiz/prelab PI principal investigator points PG personal grade Introduction: The purpose of the lab is to study the effects due to magnetic fields in motion and also to determine the qualitative features of electromagnetic induction. Procedure: 1. For the Part 1 of the lab, a solenoid was connected to a galvanometer, as shown in the data and calculations. First, the North pole was inserted into the coil, then in the opposite direction, with the South Pole first. Then, the magnitude and sign of the deflection on the galvanometer was recorded in μAmps. Also, an exact sketch is made of the solenoid, the direction of the velocity, the induced magnetic field, the induced current and the magnetic polarity of the solenoid induced in provided in the data and calculations portion of the report. 2. The magnet was inserted again following step 1, but with a faster speed and everything sketched again. Then, The South pole was inserted first and step 1 followed again for both, slow and fast speed. 3. For Part II of the lab, an electromagnet was constructed with the power supply off. In this set up the primary coil had a larger diameter wire and...
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...A Paper Presentation On “Magnetic Levitation Trains” For [pic] ABSTRACT Imagine a train that doesn't touch its track and think of the potential for lower guide way maintenance costs as a result. Imagine a train that speeds along much faster than anything on the highway with a ride as smooth as silk. Imagine that train being capable of speeds higher than any other ground-based transportation system. Maglev can provide this speed and compete directly with airline travel. As stated by American Maglev, "Maglev means magnetically levitated and propelled vehicles. The advantage of maglev is that it can achieve very high speed and acceleration/deceleration performance because the vehicles essentially "fly" at very low altitudes - unlike trains or cars; there is no surface contact or "friction" to slow them down. More speed = more passengers." Only when we have real revenue-producing systems in operation will be able to prove whether this is true or not. In Maglev—which is short for MAGNETIC LEVITATION—high speed vehicles are lifted by magnetic repulsion, and propelled along an elevated guide way by powerful magnets attached to the vehicle. The vehicles do not physically contact the guide way, do not need engines, and do not burn fuel. Instead, they are magnetically propelled by electric power fed to coils located on the guide way. Indeed this is the beginning...
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...passing magnets at the same rate as the power supply frequency and resulting rotating magnetic field which drives it. Another way of saying this is that it does not rely on slip under usual operating conditions and as a result, produces torque at synchronous speed. Synchronous motors can be contrasted with an induction, which must slip in order to produce torque. They operate synchronously with line frequency. As with squirrel-cage induction motors, speed is determined by the number of pairs of poles and the line frequency. Synchronous motors are available in sub-fractional self-excited sizes to high-horsepower direct-current excited industrial sizes. In the fractional horsepower range, most synchronous motors are used where precise constant speed is required. In high-horsepower industrial sizes, the synchronous motor provides two important functions. First, it is a highly efficient means of converting ac energy to work. Second, it can operate at leading or unity power factor and thereby provide power-factor correction. The operation of a synchronous motor is simple to imagine. The armature winding, when excited by a poly-phase (usually 3-phase) supply, creates a rotating magnetic field inside the motor. The field winding, which acts as a permanent magnet, simply locks in with the rotating magnetic field and rotates along with it. During operation, as the field locks in with the rotating magnetic field, the motor is said to be in synchronization. Once the motor is in operation...
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...Assignment 1 Energy can be converted from one form into another in three basic ways know as the action of force. The first one is gravitational forces which is when gravity accelerates a falling object, its converts its potential energy to kinetic energy. Likewise, when an object is lifted the gravitational field stores the energy exerted by the lifter as potential energy in the earth-object system. The second one is electric and magnetic force fields which is charged particles, upon which electrical fields exert forces, possess potential energy in the presence of an electric field in a way similar to that of an object in a gravitational field. These force fields can accelerate particles, converting a particle's potential energy into kinetic energy. Particles can interact via the electric and magnetic fields they create, transferring energy between them, and in the case of an electrical current in a conductor, cause molecules to vibrate, for example converting electrical potential energy into heat. This leads to the third action of force which is frictional forces(www.powerincooperation.com)This is defined as macroscopic energy of an object, that is, the potential and kinetic energy associated with the position, orientation, or motion of the entire object, not counting the thermal or heat energy of the system, can be converted into heat, whenever the object slides against another object. The sliding causes the molecules on the surfaces of contact to interact via electromagnetic...
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...The Life and Science of James Clerk Maxwell The Life and Science of James Clerk Maxwell (1831-1879) Physicist and Mathematician “The theory of relativity would have never been possible without the mathematical equations first described by James Maxwell." -Albert Einstein GRAPH James Clerk Maxwell may not be a household name when it comes to scientists, but his contributions to the field ranks him with some of the great scientists of all time.He is mainly known for his ground breaking work in electromagnetics, spurring a field that has given rise to many of the great accomplishments of the twentieth century.His equations, which relate the effects of electricity and magnetism to one another, are key in the development of modern relativity theory and the development electrical components and electronic systems.Like many great scientists, Maxwell was ahead of his time and his equations were not completely understood by his peers, but as science and mathematics progressed the beauty and genius behind his equations was fully revealed. On June 13, 1831, James Clerk Maxwell was born in Edinburgh, Scotland.With the exception of an older sister that died at a young age, he was an only child.His father, John, was a lawyer who was in his forties by the time James was born.John was considered to be an intelligent, but somewhat eccentric man.When James was young, his mother, Frances Cay, died after a prolonged illness (believed now to be cancer).After his mother’s passing...
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...Energy can be converted from one form into another in three basic ways know as the action of force. The first one is gravitational forces which is when gravity accelerates a falling object, its converts its potential energy to kinetic energy. Likewise, when an object is lifted the gravitational field stores the energy exerted by the lifter as potential energy in the earth-object system. The second one is electric and magnetic force fields which is charged particles, upon which electrical fields exert forces, possess potential energy in the presence of an electric field in a way similar to that of an object in a gravitational field. These force fields can accelerate particles, converting a particle's potential energy into kinetic energy. Particles can interact via the electric and magnetic fields they create, transferring energy between them, and in the case of an electrical current in a conductor, cause molecules to vibrate, for example converting electrical potential energy into heat. This leads to the third action of force which is frictional forces(www.powerincooperation.com)This is defined as macroscopic energy of an object, that is, the potential and kinetic energy associated with the position, orientation, or motion of the entire object, not counting the thermal or heat energy of the system, can be converted into heat, whenever the object slides against another object. The sliding causes the molecules on the surfaces of contact to interact via electromagnetic fields with...
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...INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL N00/430/H(1) PHYSICS HIGHER LEVEL PAPER 1 Friday 10 November 2000 (afternoon) 1 hour INSTRUCTIONS TO CANDIDATES ! ! ! Do not open this examination paper until instructed to do so. Answer all the questions. For each question, choose the answer you consider to be the best and indicate your choice on the answer sheet provided. 880-226 24 pages –2– 1. N00/430/H(1) When an ideal gas in a thermally insulated chamber is compressed the volume V and pressure P are related by the equation PV γ = constant where γ is a constant. Which one of the following plots would produce a straight-line graph? 1 V A. B. log P against log V C. P against log V D. 2. P against log P against V The power P dissipated in a resistor of resistance R in which there is a current I is given by P = I2 R The uncertainty in the value of resistance of a particular resistor is !10% and the uncertainty in the value of the current in the resistor is !3%. The best estimate for the uncertainty of the power dissipated is A. B. !9%. C. !16%. D. 3. !6%. ±19%. When a car is moving at a speed v in a straight line the total force opposing its motion is F. The product Fv is a measure of the A. power developed by the car. B. rate of change of momentum of the car. C. work done by the car against the frictional forces. D. ...
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...and that the conventional formulation of apelture theory violates a basic condition of the equivalence principle. A new apermre theory formulation is presented. The method is very simple to implement and will be shown to be exact in as far as the exact aperture fields are known. II. THE SURFACE EQUIVALENCE THEOREM REVISITED Consider Love's external equivalence as discussed in [3]. Sources 3, and-i radQte in free space (E,, @,)andtogether with equivalent surface current densities ., I and hl , on n ! equiv_alentsurfaces, typically'enclos$g' an eiecuomagnetic scatterer,produce the m e fields E, and H external to-Sand $1 fields 5 and H internal to S. The surface current densities are given by J, = ti x HI , M, = -ii x €,The electric and magnetic fields can be...
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...preparing for an evening lecture on 21 April 1820, he made surprise observation. As he was setting up the materials, he noticed a compass needle deflected from magnetic north when the electric current from the battery he was using switched on and off. This deflection convinced him that magnetic fields radiate from all sides of wire carrying an electric current, just as light and heat do, and that it confirmed a direct relationship between electricity and magnetism. He published his findings, proving that an electric current produces a magnetic field as it flows through a wire. The CGS unit of magnetic induction is named in honor of his contributions to the field of electromagnetism. The magnetic field encircles this straight piece of current- carrying wire, the magnetic flux lines having no definite “north” or “south” poles. While the magnetic field surrounding a current- carrying wire is indeed interesting, it is quiet weak for common amounts of current, able to deflect a compass needle and not much more. To create a stronger magnetic field force (and consequently, more field flux) with the same amount of electric current, we can wrap the wire into a coil shape, where the circling magnetic fields around the wire will join to create a larger field with a definitemagnetic (north and south) polarity; the amount of magnetic field force generated by a coiled wire is proportional to the current through the wire multiplied by the number of “turns” or “wraps” of wire in the coil. This...
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