Electromagnetic induction & useful applications
Download as PPTX, PDF8 likes13,340 views
This document is a presentation on electromagnetic induction and its applications by a group of students. It discusses the history of electromagnetic induction discovered by Faraday, defines electromagnetic induction as occurring when a changing magnetic flux induces an emf in a conductor, and outlines Faraday's laws of electromagnetic induction. It also explains Lenz's law and Fleming's right hand rule for determining the direction of induced current. Finally, it provides examples of useful applications of electromagnetic induction such as AC generators, electric motors, magnetic recording devices, electric stoves, and magnetic brakes.
Electromagnetic induction & useful applications
- 1. Electromagnetic Induction & Its Applications PHY123 Presentation Group: ASTUTE • Tasnuva Tabassum Oshin: 151-15-4673 • Masumer Rahman: 151-15-5040 • Mariya Rahman: 151-15-5317 • T.M Ashikur Rahman: 151-15-4971 • Soummo Suprya: 151-15-4741 • Md. Fazle Rabbi Ador: 151-15-5482
- 2. introduction History of Electromagnetic Induction. What is Electromagnetic Induction? Requirements of Electromagnetic induction Amount of Induced e.m.f. Faraday’s Law of Electromagnetic Induction Direction of Induced emf and Current Lenz’s Law Direction of Induced emf and Current Fleming’s Right Hand Rule Useful applications
- 4. History ofElectromagnetic Induction *Almost 200 years ago, Faraday looked for evidence that a magnetic field would induce an electric current with this apparatus. *He found no evidence when the magnet was steady, but did see a current induced when the magnet moves up and down .
- 5. Faraday learned that if you change any part of the flux over time you could induce a current in a conductor and thus create a source of EMF (voltage, potential difference). History ofElectromagnetic Induction
- 6. What is Electromagnetic Induction? When the Magnetic flux linking with a conductor or coil and changes an e.m.f. is induced in the conductor. If the conductor forms a complete loop or circuit, a current will flow in it, that’s called the Electromagnetic Induction.
- 8. Requirements of Electromagnetic induction 1) The first and basic requirement for electromagnetic induction is the change in Flux linking with the conductor (or coil). 2) The e.m.f. and hence the current in this conductor (or coil) will persist so long as this change is taking place. 3)The requirement is not only linking the coil with the Flux, the main thing is, if we want to induced some e.m.f. The Flux should be change after linking with coil.
- 9. Amount of Induced e.m.f: The amount of induced e.m.f. in a coil is directly proportional to---- 1) the number of turn on the coil, 2) the rate change the Flux linking with coil.
- 10. Amount of Induced e.m.f: t NN t N eortheChangTimeTakenf uxChangeofFl N geofFluxrateofChanN 12 )12( Induced emf is Here, N= Number of Turn of Coil = the change of Flux linking by conductor t= time of changing the flux
- 12. Faraday’s Law of Electromagnetic Induction:- Faraday performed a series of experiments to the phenomenon of electromagnetic induction. He performed two laws about electromagnetic induction a known as Faraday’s law:-
- 13. Faraday’s Law of Electromagnetic Induction:- First Law: “When the Changes Flux linking with a conductor or coil, an emf is Induced in it.”
- 14. Faraday’s Law of Electromagnetic Induction:- Second Law: “The magnitude of induced emf in a coil is directly proportional to the rate of change of flux linkages”
- 16. The direction of Induced emf and hence current in conductor or coil can be determined by one of the following methods: 1. Lenz’s Law 2. Fleming’s Right hand Rule. Directionof Inducede.m.f andCurrent Lenz’s Law
- 17. 1) Lenz’s Law:- Email Lenz, observed that the direction of induced emf has a defined relation to change of magnetic field that produces it. He gave the simple following simple rule:- “An Induced Current will flow in such a Direction so as to oppose the cause that produces it.” Directionof Inducede.m.f and Current Lenz’s Law
- 18. • The cause that the change of produces current is the change of flux linking the coil. Therefore, the direction of induced current will be such that its own magnetic field oppose the change in flux that produced the induced current. • That means the induced current on its conductor or coil will be the oppose direction of the original flux direction. Directionof Inducede.m.f and Current Lenz’s Law
- 19. We know that, the magnetic flux always flow through from North pole to South pole. So, Current will be flow through from South to North. Directionof Inducede.m.f and Current Lenz’s Law
- 21. DirectionofInduced emfand Current Fleming’s Right Hand Rule • This is the Rule of particularly suitable to find the direction of Induced emf and hence current when the conductor moves at right angles to a stationary magnetic field. • Stretch out the Four finger, Middle finer and thumb of Your right hand so that they are at right angles to one another.
- 22. DirectionofInduced emfand Current Fleming’s Right Hand Rule “If the forefinger points to direction of the magnetic field, Thumb is the direction of motion the conductor, then the middle finger will point in the direction to the Induced Current.”
- 23. DirectionofInduced emfand Current Fleming’s Right Hand Rule Consider that, A Conductor is Moving as the direction of Forefinger, the magnetic flux is go through from the north to south pole as the same direction of Thumb finger, now Current will be flow as the same direction of the middle finger.
- 26. AC Generator AC Generators use Faraday’s law to produce rotation and thus convert electrical and magnetic energy into rotational kinetic energy. This idea can be used to run all kinds of motors.
- 27. Electro magnetic induction can create an electrical motor by passing a current through a set of electro- magnets mounted on a rotating shaft. ELECTRIC MOTOR
- 28. MAGNETIC RECORDS Write data by magnetizing recording media (e.g., video tape, hard disk) using electromagnets. Data is read back using the induced current produced when magnetized media moves past receiver coils (reverse of writing data).
- 29. ELECTRIC STOVES The water in the metal pot is boiling. Yet, the water in the glass pot is not boiling, and the stove top is cool to the touch. The stove operates in this way by using electromagnetic induction.
- 30. MAGNETIC BRAKES Great America’s Drop Zone has a 22 story free fall, lasting four seconds, decelerated by magnetic braking.
- 31. QUESTION?? ?