DOCSLIB.ORG

Faraday's Law Da

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Faraday's Law Da Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Applications of Magnetic Induction • AC Generator – Water turns wheel Æ rotates magnet Æ changes flux Æ induces emf Æ drives current • “Dynamic” Microphones (E.g., some telephones) – Sound Æ oscillating pressure waves Æ oscillating [diaphragm + coil] Æ oscillating magnetic flux Æ oscillating induced emf Æ oscillating current in wire Question: Do dynamic microphones need a battery? More Applications of Magnetic Induction • Tape / Hard Drive / ZIP Readout – Tiny coil responds to change in flux as the magnetic domains (encoding 0’s or 1’s) go by. 2007 Nobel Prize!!!!!!!! Giant Magnetoresistance • Credit Card Reader – Must swipe card Æ generates changing flux – Faster swipe Æ bigger signal More Applications of Magnetic Induction • Magnetic Levitation (Maglev) Trains – Induced surface (“eddy”) currents produce field in opposite direction Æ Repels magnet Æ Levitates train S N rails “eddy” current – Maglev trains today can travel up to 310 mph Æ Twice the speed of Amtrak’s fastest conventional train! – May eventually use superconducting loops to produce B-field Æ No power dissipation in resistance of wires! Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface. A The choice of vector A direction defines the direction of EMF with a right hand rule. Your thumb in A direction and then your fingers point to positive EMF direction. Lenz’s Law – easier way! The direction of any magnetic induction effect is such as to oppose the cause of the effect. ⇒ Convenient method to determine I direction Heinrich Friedrich Example if an external magnetic field on a loop Emil Lenz is increasing, the induced current creates a field opposite that reduces the net field. (1804-1865) Example if an external magnetic field on a loop is decreasing, the induced current creates a field parallel to the that tends to increase the net field. Lecture 16, Act 2 y • A conducting rectangular loop moves with constant velocity v in the +x direction X X X X X X X X X X X X through a region of constant magnetic field B X X X X X X X X X X X X in the -z direction as shown. X X X X X X X vX X X X X X X X X X X X X X X X X 2A • What is the direction of the induced current in the loop? x (a) ccw (b) cw (c) no induced current • A conducting rectangular loop moves with y I constant velocity v in the -y direction and a constant current I flows in the +x direction as shown. • What is the direction of the induced 2B v current in the loop? x (a) ccw (b) cw (c) no induced current Lecture 16, Act 2 y • A conducting rectangular loop moves with constant velocity v in the +x direction X X X X X X X X X X X X through a region of constant magnetic field B X X X X X X X X X X X X in the -z direction as shown. X X X X X X X vX X X X X X X X X X X X X X X X X 1A2A – What is the direction of the induced current in the loop? x (a) ccw (b) cw (c) no induced current • There is a non-zero flux ΦB passing through the loop since B is perpendicular to the area of the loop. • Since the velocity of the loop and the magnetic field are CONSTANT, however, this flux DOES NOT CHANGE IN TIME. • Therefore, there is NO emf induced in the loop; NO current will flow!! Lecture 16, Act 2 • A conducting rectangular loop moves with y I constant velocity v in the -y direction and a constant current I flows in the +x direction as shown. • What is the direction of the induced 2B current in the loop? v x (a) ccw (b) cw (c) no induced current • The flux through this loop DOES change in time since the loop is moving from a region of higher magnetic field to a region of lower field. • Therefore, by Lenz’ Law, an emf will be induced which will oppose the change in flux. • Current is induced in the clockwise direction to restore the flux. Y&F Problem 29.2 In a physics laboratory experiment, a coil with 200 turns enclosing an area of 122cm^2 is rotated in a time interval of 0.04s from a position where its plane is perpendcular to thie earth's magnetic field to one where its plane is parallel to the field. The earth's magnetic field at the lab location is 6x10(-5)T. What is the total magnetic flux through the coil before it is rotated? What is the total magnetic flux through the coil after it is rotated? What is the average emf induced in the coil? B r r ΦB = d A • Bcos = o 0 dA= BA i ∫∫ ( 6 10x= )( T 0−5 . 0122 m2 = ) x−7 7 . 2 31Tm 10 Φf cosBA = 90= 0 Φ() −7 Φ .x 31−7 10 Tm 2 ε= − f i = + 1 .= 83x−5 10 Tm 2 Δt 0 . 04s Incredible shrinking loop: a circular loop of wire with a magnetic flux is shrinking with time. In which direction is the induced current? (a) There is none. (b) CW. (c) CCW X X X X X X X X X X X X X X X X X X X X X X X X Determine the direction of the induced current in a – b when 1.) Switch is opened after having been closed for a long time. (a) No current. (b) left to right. (c) right to left. 2.) The resistance R is decreased while switch remains closed. (a) No current. (b) left to right. (c) right to left. Slide Wire Generator S The area is LS(t) and dS/dt quals velocity of slidere d d r r d = −ε Φ = −B d • A B = dA − dt B dt∫dt ∫ d d d = − =BA −BLS =S − BL BLv = − dt dt dt Direction of current and ε as shown from Lenz’s Law. Slide Wire Generator; work and power we found ε = BLv we now ask what is power dissipated, Pd and power applied, Pa S assume total resistance is R, then I=Ɛ/R and 2 2 2 2 Pd =I R=B L v /R The power applied, Pa=Fv, is the rate of work to the bar to the right against the force, F, which is pointed to the left. F=ILB= (Ɛ/R)LB = 2 2 2 2 2 B L v/R. Thus Pa= Fv = B L v /R = Pd and we find the power put into the moving the bar equals the heat dissipated in the circuit. ⇒ Power needed to move bar = Power dissipated in circuit Slide Wire Generator; use Lenz’s Law to get I direction Lenz’s Law says direction creates field that opposes S change in magnetic flux. If we pull bar to right, the net magnetic flux in rectangle increases into screen, hence the I direction must induce opposite B field which is out of screen and is correct in drawing. Suppose Lenz’s law were reversed, then I would be reversed and F would go right and the bar would be accelerated to the right, w/o need of external positive work and heat would be dissipated at the same time. This violates Conservation of Energy, so Lenz’s law is correct. Motional Electromotive Force d r r dΦ =ε −B∫ d ⋅= A − B dt dt In Faraday’s Law, we can induce EMF in the loop when the magnetic flux, ΦB, changes as a function of time. There are two Cases when ΦB is changing, 1) Change the magnetic field (non-constant over time) 2) Change or move the loop in a constant magnetic field The slide wire generator is an example of #2 and the induction of EMF via moving parts of the loop is called, motional EMF. roernator GeneratAlt Wire loop area A rotates with respect to constant magnetic field. r r ΦB = d • A =cos BAφ B ∫ If the angular frequency is ω, then ΦB = BAcos(ωt) d Φ =BAω − sin() ω t dt B and EMF in the loop is d =ε − ΦBAω = sin() ω t dt B Slide Wire Generator; revisited again B E E Suppose we move a conducting bar in a constant B field, then a force FB =q v×B moves + charge up and – charge down. The charge distribution produces an electric field, E, force, FE, and EMF, Ɛ, between a & b. This continues until equilibrium is reached: FE = -FB. r r r b r F − F q vr × B r r r E=E = B= − =v −r × B εE=∫ d ⋅ l= vBl q q q a In effect the bar motional EMF is an equivalent to a battery EMF Slide Wire Generator; revisited again If the rod is on the U shaped conductor, the charges don’t build up at the ends but move around the U shaped portion.
Load more

Recommended publications
  • Introduction to Direct Current (DC) Theory
    PDHonline Course E235 (4 PDH) Electrical Fundamentals - Introduction to Direct Current (DC) Theory Instructor: A. Bhatia, B.E. 2012 PDH Online | PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax: 703-988-0088 www.PDHonline.org www.PDHcenter.com An Approved Continuing Education Provider CHAPTER 3 DIRECT CURRENT LEARNING OBJECTIVES Upon completing this chapter, you will be able to: 1. Identify the term schematic diagram and identify the components in a circuit from a simple schematic diagram. 2. State the equation for Ohm's law and describe the effects on current caused by changes in a circuit. 3. Given simple graphs of current versus power and voltage versus power, determine the value of circuit power for a given current and voltage. 4. Identify the term power, and state three formulas for computing power. 5. Compute circuit and component power in series, parallel, and combination circuits. 6. Compute the efficiency of an electrical device. 7. Solve for unknown quantities of resistance, current, and voltage in a series circuit. 8. Describe how voltage polarities are assigned to the voltage drops across resistors when Kirchhoff's voltage law is used. 9. State the voltage at the reference point in a circuit. 10. Define open and short circuits and describe their effects on a circuit. 11. State the meaning of the term source resistance and describe its effect on a circuit. 12. Describe in terms of circuit values the circuit condition needed for maximum power transfer. 13. Compute efficiency of power transfer in a circuit. 14. Solve for unknown quantities of resistance, current, and voltage in a parallel circuit.
    [Show full text]
  • A Dc–Dc Converter with High-Voltage Step-Up Ratio and Reduced- Voltage Stress for Renewable Energy Generation Systems
    A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS A Dissertation by Satya Veera Pavan Kumar Maddukuri Master of Science, University of Greenwich, UK, 2012 Bachelor of Technology, Jawaharlal Nehru Technology University Kakinada, India, 2010 Submitted to the Department of Electrical Engineering and Computer Science and the faculty of the Graduate School of Wichita State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2018 1 © Copyright 2018 by Satya Veera Pavan Kumar Maddukuri All Rights Reserved 1 A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS The following faculty members have examined the final copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirement for the degree of Doctor of Philosophy with a major in Electrical Engineering and Computer Science. ___________________________________ Aravinthan Visvakumar, Committee Chair ___________________________________ M. Edwin Sawan, Committee Member ___________________________________ Ward T. Jewell, Committee Member ___________________________________ Chengzong Pang, Committee Member ___________________________________ Thomas K. Delillo, Committee Member Accepted for the College of Engineering ___________________________________ Steven Skinner, Interim Dean Accepted for the Graduate School ___________________________________ Dennis Livesay, Dean iii DEDICATION To my parents, my wife, my in-laws, my teachers, and my dear friends iv ACKNOWLEDGMENTS Firstly, I would like to express my sincere gratitude to my advisor Dr. Aravinthan Visvakumar for the continuous support of my PhD study and related research, for his thoughtful patience, motivation, and immense knowledge. His guidance helped me in all the time of research and writing of this dissertation.
    [Show full text]
  • Instructor's Guide
    Instructor’s Guide Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM Introduction This instructor’s guide provides information to help you get the most out of Electricity and Magnetism, part of the eight-part series Electricity: A 3-D Animated Demonstration. The series makes the principles of electricity easier to understand and discuss. The series includes Electrostatics; Electric Current; Ohm's Law; Circuits; Power and Efficiency; Electricity and Magnetism; Electric Motors; and Electric Generators. Electricity and Magnetism traces the relationship between magnetism and electricity from the first accidental discovery of induced current. Learning Objectives After watching the video program, students will be able to: • Describe the relationship between electricity and magnetism • Explain the difference between electric and magnetic fields • Explain the construct, function, and use of solenoids • Differentiate between, explain, and apply the left-hand and right-hand rules • Demonstrate (via experiments) and explain aspects, and actions and functions of electricity, magnetism, and electromagnetism Educational Standards National Science Standards This program correlates with the National Science Education Standards from the National Academies of Science, and Project 2061, from the American Association for the Advancement of Science. Copyright © 2008 SHOPWARE® • www.shopware-usa.com • 1-800-487-3392 Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM INSTRUCTOR’S GUIDE Science as Inquiry Content Standard A:
    [Show full text]
  • The Concept of Field in the History of Electromagnetism
    The concept of field in the history of electromagnetism Giovanni Miano Department of Electrical Engineering University of Naples Federico II ET2011-XXVII Riunione Annuale dei Ricercatori di Elettrotecnica Bologna 16-17 giugno 2011 Celebration of the 150th Birthday of Maxwell’s Equations 150 years ago (on March 1861) a young Maxwell (30 years old) published the first part of the paper On physical lines of force in which he wrote down the equations that, by bringing together the physics of electricity and magnetism, laid the foundations for electromagnetism and modern physics. Statue of Maxwell with its dog Toby. Plaque on E-side of the statue. Edinburgh, George Street. Talk Outline ! A brief survey of the birth of the electromagnetism: a long and intriguing story ! A rapid comparison of Weber’s electrodynamics and Maxwell’s theory: “direct action at distance” and “field theory” General References E. T. Wittaker, Theories of Aether and Electricity, Longam, Green and Co., London, 1910. O. Darrigol, Electrodynamics from Ampère to Einste in, Oxford University Press, 2000. O. M. Bucci, The Genesis of Maxwell’s Equations, in “History of Wireless”, T. K. Sarkar et al. Eds., Wiley-Interscience, 2006. Magnetism and Electricity In 1600 Gilbert published the “De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure” (On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth). ! The Earth is magnetic ()*+(,-.*, Magnesia ad Sipylum) and this is why a compass points north. ! In a quite large class of bodies (glass, sulphur, …) the friction induces the same effect observed in the amber (!"#$%&'(, Elektron). Gilbert gave to it the name “electricus”.
    [Show full text]
  • Faraday's Law Da
    Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface. A The choice of vector A direction defines the direction of EMF with a right hand rule. Your thumb in A direction and then your fingers point to positive EMF direction. Lenz’s Law – easier way! The direction of any magnetic induction effect is such as to oppose the cause of the effect. ⇒ Convenient method to determine I direction Heinrich Friedrich Example if an external magnetic field on a loop Emil Lenz is increasing, the induced current creates a field opposite that reduces the net field. (1804-1865) Example if an external magnetic field on a loop is decreasing, the induced current creates a field parallel to the that tends to increase the net field. Incredible shrinking loop: a circular loop of wire with a magnetic flux is shrinking with time. In which direction is the induced current? (a) There is none. (b) CW.
    [Show full text]
  • Teaching H. C. Ørsted's Scientific Work in Danish High School Physics
    UNIVERSITY OF COPENHAGEN FACULTY OF SCIENCE Ida Marie Monberg Hindsholm Teaching H. C. Ørsted's Scientific Work in Danish High School Physics Masterʹs thesis Department of Science Education 19 July 2018 Master's thesis Teaching H. C. Ørsted’s Scientific Work in Danish High School Physics Submitted 19 July 2018 Author Ida Marie Monberg Hindsholm, B.Sc. E-mail [email protected] Departments Niels Bohr Institute, University of Copenhagen Department of Science Education, University of Copenhagen Main supervisor Ricardo Avelar Sotomaior Karam, Associate Professor, Department of Science Education, University of Copenhagen Co-supervisor Steen Harle Hansen, Associate Professor, Niels Bohr Institute, University of Copenhagen 1 Contents 1 Introduction . 1 2 The Material: H. C. Ørsted's Work . 3 2.1 The Life of Hans Christian Ørsted . 3 2.2 Ørsted’s Metaphysical Framework: The Dynamical Sys- tem............................. 6 2.3 Ritter and the failure in Paris . 9 2.4 Ørsted’s work with acoustic and electric figures . 12 2.5 The discovery of electromagnetism . 16 2.6 What I Use for the Teaching Sequence . 19 3 Didactic Theory . 20 3.1 Constructivist teaching . 20 3.2 Inquiry Teaching . 22 3.3 HIPST . 24 4 The Purpose and Design of the Teaching Sequence . 27 4.1 Factual details and lesson plan . 28 5 Analysis of Transcripts and Writings . 40 5.1 Method of Analysis . 40 5.2 Practical Problems . 41 5.3 Reading Original Ørsted's Texts . 42 5.4 Inquiry and Experiments . 43 5.5 "Role play" - Thinking like Ørsted . 48 5.6 The Reflection Corner . 51 5.7 Evaluation: The Learning Objectives .
    [Show full text]
  • AC Vs. DC Boost Converters: a Detailed Conduction Loss Comparison
    AC vs. DC Boost Converters: A Detailed Conduction Loss Comparison Daniel L Gerber Fariborz Musavi Building Technology and Urban Systems Engineering and Computer Science Lawrence Berkeley Labs Washington State University Berkeley, CA, USA Vancouver, WA, USA [email protected] [email protected] Abstract—Studies have shown the efficiency benefits of DC dis- at the same voltage. Although several previous works have tribution systems are largely due to the superior performance of analyzed and established loss models for the DC/DC [9]– DC/DC converters. Nonetheless, these studies are often based on [12] and AC/DC PFC [13]–[20] boost converters, they each product data that differs widely in manufacturer and operating have their own methods and formulae, making an analytic voltage. This work develops a rigorous loss model to theoretically comparison difficult. In addition, many of them neglect es- compare the efficiency of a DC/DC and an AC/DC PFC boost sential components such as the input bridge drop and output converter. It ensures each converter has the same components and equivalent operating voltages. The results show AC boost capacitor equivalent series resistance (ESR). This is the first converters below 500 W to have 2.9 to 4.2 times the loss of DC. work to establish a set of formulae that compare the loss between an AC and DC boost converter, both of which have the Keywords—DC microgrid, boost converter, loss model, power same components and equivalent operating voltages. Although factor correction DC/DC converters are already known to be more efficient, this work reports exactly how much more.
    [Show full text]
  • DIRECT CURRENT CIRCUITS I [Written by Suzanne Amador Kane; Modified Slightly for Our Purposes.] Readings: Serway, Chapters 27–28
    DIRECT CURRENT CIRCUITS I [Written by Suzanne Amador Kane; Modified slightly for our purposes.] Readings: Serway, Chapters 27–28. At long last we are ready to begin work with Direct Current (DC) Circuits. DC circuits are those in which the voltages and currents are constant, or time-independent. Time-dependent circuits in which the current oscillates periodically are referred to as Alternating Current (AC) circuits. We will study AC circuits soon enough. As you know, charge is the fundamental unit of electricity much as mass is the fundamental unit of gravitation. A significant difference is that mass is always positive (as far as we know), while charge can be either positive or negative. When charges flow, they form a current, just as when mass moves it has momentum. If we drop a mass, it "flows" down to a lower potential, and a potential difference in an electric circuit drives a current to the lower potential from the higher potential. Since charges come in both positive and negative flavors, electrical potential drives some charges up while others flow down. By analogy, if there were negative mass, it would fall up. When a ball is dropped into a liquid, it falls more slowly due to the resistance of the liquid. Likewise, in a circuit we insert a "resistor" which impedes the flow of current. In a circuit, the effect is to lower the rate at which charge moves, effectively lowering the current which flows through the circuit. It is useful to note here that if we did not have a resistor, in effect it would be like dropping a huge object onto the Earth without air resistance – look at the craters on the Moon to see how undesirable this would be! In circuits, this is called a "short circuit" and it quickly drains the potential while also risking serious damage to the components (and the experimenter).
    [Show full text]
  • DC Power Production, Delivery and Utilization
    DDCC PPowerower PProduction,roduction, DDeliveryelivery aandnd UUtilizationtilization An EPRI White Paper June 2006 AAnn EEPRIPRI WWhitehite PPaperaper DC Power Production, Delivery and Utilization This paper was prepared by Karen George of EPRI Solutions, Inc., based on technical material from: Arshad Mansoor, Vice President, EPRI Solutions Clark Gellings, Vice President—Innovation, EPRI Dan Rastler, Tech Leader, Distributed Resources, EPRI Don Von Dollen, Program Director, IntelliGrid, EPRI AAcknowledgementscknowledgements We would like to thank reviewers and contributors: Phil Barker, Principal Engineer, Nova Energy Specialists David Geary, Vice President, of Engineering, Baldwin Technologies, Inc. Haresh Kamath, EPRI Solutions Tom Key, Principal Technical Manager, EPRI Annabelle Pratt, Power Architect, Intel Corporation Mark Robinson, Vice President, Nextek Power Copyright ©2006 Electric Power Research Institute (EPRI), Palo Alto, CA USA June 2006 Page 2 AAnn EEPRIPRI WWhitehite PPaperaper DC Power Production, Delivery and Utilization Edison Redux: The New AC/DC Debate Thomas Edison’s nineteenth-century electric distribution sys- Several converging factors have spurred the recent interest in tem relied on direct current (DC) power generation, delivery, DC power delivery. One of the most important is that an in- and use. This pioneering system, however, turned out to be im- creasing number of microprocessor-based electronic devices practical and uneconomical, largely because in the 19th cen- use DC power internally, converted inside the device from tury, DC power generation was limited to a relatively low volt- standard AC supply. Another factor is that new distributed re- age potential and DC power could not be transmitted beyond sources such as solar photovoltaic (PV) arrays and fuel cells a mile.
    [Show full text]
  • Electromagnetic Coil Gun – Design and Construction
    Bohumil SKALA Vladimir KINDL ELECTROMAGNETIC COIL GUN – DESIGN AND CONSTRUCTION ABSTRACT A single-stage, sensor less, coil gun was designed to demonstrate the capability to accelerate a ferromagnetic projectile to high velocity. This paper summarize all important steps during coil gun design, such as physical laws of the coil gun, preliminary calculations, the testing device and final product. The electromagnetic FEA model of the capacitor-driven inductance coil gun was constructed to be able to optimize the coil's dimensions. The driving circuit was implemented as dynamic model for simulation of current. The coil gun is designed for an exhibition centre as an exhibit. It is not designed for a really shooting applications, this means the projectile is accelerated at relatively low speed. Keywords: Coil gun, electronics, FEM, electromagnetic force 1. INTRODUCTION Electromagnetic accelerating systems are usually constructed as rail guns [3] or coil guns [1]. The rail gun is conceptually more simple than the coil gun, but has some inherent problems with plasma [2] during the projectile launches. That is why this conception is not use here. On the other hand the coil gun is much more suitable for common applications even if it needs some additional supporting facilities [4] such as energy accumulator, switcher and driver. Its main advantage lies in loose of almost all negative phenomena damaging the launch device. Doc. Ing. Bohumil SKALA, Ph.D. e-mail: [email protected] Ing. Vladimir KINDL, Ph.D. e-mail: [email protected] Dept. of Electromechanics and Power Electronics, University of West Bohemia in Pilsen, Univerzitní 8, 306 14 Pilsen, CZ PROCEEDINGS OF ELECTROTECHNICAL INSTITUTE, Issue 263, 2013 116 B.
    [Show full text]
  • Electromagnetic Coil Gun Launcher System
    ISSN(Online): 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (A High Impact Factor, Monthly, Peer Reviewed Journal) Visit: www.ijirset.com Vol. 8, Issue 3, March 2019 Electromagnetic Coil Gun Launcher System Prof. Yogesh Fatangde1 Swapnil Biradar2, Aniket Bahmne3, Suraj Yadav4, Ajay Yadav5 Department of Mechanical Engineering, RMD Sinhgad Technical Campus, Savitribai Phule Pune University, Pune, Maharashtra, India1 ABSTRACT: In our present time, a study was undertaken to determine if ground based electromagnetic acceleration system could provide a useful reduction in launching cost with current large chemical boosters, while increasing launch safety and reliability. An electromagnetic launcher (EML) system accelerates and launches a projectile by converting electric energy into kinetic energy. An EML system launches projectile by converting electric energy into kinetic energy. There are two types of EML system under development: rail gun and coil gun. A coil gun launches the projectile by magnetic force of electromagnetic coil. A higher velocity needs multiple stages of system, which make coil gun EML system longer. As a result installation cost is very high and it required large installation site for EML. So, we present coil gun EML system with new structure and arrangement for multiple electromagnetic coils to reduce the length of system KEYWORDS: EML, coil gun, Electromagnetic launcher, suck back effect I. INTRODUCTION In chemical launcher systems such as firearms and satellite launchers, chemical explosive energy is converted into mechanical dynamic energy. The system must be redesigned and remanufactured if the target velocity of the projectile is changed. In addition, such systems are not eco-friendly.
    [Show full text]
  • Electromagnetic Induction Go Back in Time
    Electromagnetic Induction Many electrical or electronic devices rely on a principle called electromagnetic induction in order to function. The term refers to electricity being produced in a conductor by a changing magnetic field. To understand it better, it helps to go back in time. This phenomenon was first observed byMichael Faraday in 1831 A conductor is the term and, realizing that this was an important discovery, he carried given to a material whose electrons will out a number of experiments to determine exactly what was move easily from one happening. He noticed that: atom to another. • When the magnetic flux linking a conductor changes then an electromotive force is induced in the conductor. • The magnitude of the emf induced in the inductor is proportional to the rate of change of the flux linkage. The above relates to one of Faraday’s laws. In simple terms, it means that if a conductor is moved within a magnetic field then the force it experiences causes an electric current to flow through that conductor. Likewise, the faster the change in the magnetic field then the greater the emf produced. 47 The important thing to remember is that the electromotive force will only be produced in the conductor as long as the magnetic field is changing – therefore, no change, no current flow! A typical conductor is a Other experiments length of copper wire. Michael Faraday was not the only one to have observed the phenomenon. Working independently, the American scientist Joseph Henry also discovered electromagnetic induction at about the same time as Faraday. In recognition, the henry (symbol H) is now the SI unit of inductance.
    [Show full text]