Electromagnetic Induction Q2Lesson2 PDF
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Uploaded by PlentifulOnyx4387
Yonsei University
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Summary
These notes cover the topic of electromagnetic induction, discussing Faraday's Law, Lenz's Law, and how these principles apply to different systems. Key concepts such as electromagnets and solenoids are examined. The study materials also showcase visuals including diagrams. For example, these demonstrate the concepts.
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HANS CHRISTIAN OERSTED ? Was the first to show that an electric current can produce magnetic fields ? Discovered the relationship of electricity and magnetism during a class demonstration that a current carrying wire caused a nearby magnetized compass needle to defle...
HANS CHRISTIAN OERSTED ? Was the first to show that an electric current can produce magnetic fields ? Discovered the relationship of electricity and magnetism during a class demonstration that a current carrying wire caused a nearby magnetized compass needle to deflect ? Electromagnets – are tightly wound helical coil of wire, usually with an iron core, which acts like a permanent magnet when current is flowing in the wire. 3 WAYS TO CHANGE THE STRENGTH OF AN ELECTROMAGNET ? Increase the no. of turns of the coil ? Increase the current ? Using an iron core SOLENOID ? a type of electromagnet when the purpose is to generate a controlled magnetic field. USES OF ELECTROMAGNETS ? Electromagnets are very widely used in electric and electromechanical devices like motors, generators, transformer, electric bells, buzzers, loudspeakers and earphones. ? Magnetic separation equipment used for separating magnetic from non magnetic materials. ? Industrial lifting magnets ? Electromagnetic suspension used for maglev train ELECTROMAGNETIC INDUCTION Production of electric current across a conductor when exposed to a changing magnetic field FARADAY’S LAW OF ELECTROMAGNETIC INDUCTION (MICHAEL FARADAY) ? Any change in the magnetic field of a coil of wire will cause an emf to be induced in the coil. ? This emf induced is called induced emf and if the conductor circuit is closed, the current will also circulate through the circuit and this current is called induced current. FACTORS THAT DETERMINE THE AMOUNT OF INDUCED CURRENT 1. Moving the coil or the magnet faster 2. Increasing strength of the magnetic field 3. Increasing the number of turns/ length of the coil LENZ’S LAW (HEINRICH LENZ) ? Thedirection of the induced emf or induced current is such that it opposes the change that is producing it. MAGNETIC FIELD IN A STRAIGHT CONDUCTOR Thumb – current Fingers –magnetic field MAGNETIC FIELD IN A LOOPED CONDUCTOR FLEMING’S LEFT HAND RULE/RIGHT HAND RULE (JOHN AMBROSE FLEMING) ? Todetermine the direction of the magnetic field, current and force (applicable in electric motor)
