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Magnetism Notes. Magnets. Magnetic domain – region of a magnetic material where the atoms are groups together and aligned Has uniform magnetization. Magnets. Poles of a magnet are the ends where objects are most strongly attracted 2 poles called North and South Like poles repel
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Magnets • Magnetic domain – region of a magnetic material where the atoms are groups together and aligned • Has uniform magnetization
Magnets • Poles of a magnet are the ends where objects are most strongly attracted • 2 poles called North and South • Like poles repel • Opposite poles attract • If a magnet is broken into 2 pieces, each piece will still have an N and S
Magnets • Iron is the most common magnetic material • Unmagnetized iron can be magnetized via conduction (stroking) or induction
Magnetic Field • The region of space surrounding a moving charge • Is a vector quantity (arrows)
Magnetic Field Attraction Repulsion
Electromagnet • Electric current produces a magnetic field • Made from current flowing through coils of wire (called a solenoid) • Faraday’s Law: More coils = stronger electromagnet (more voltage)
Motors and Generators Motors and Generators Video PBS AC Generator Animation
Just Kidding! But Seriously….
Electrical Transformers • Device that transfers energy and changes the amount of voltage • Has 2 winding circuits and current varies between them causing magnetic flux (a measure of the amount of magnetic field passing through a given surface)
Electrical Transformers • Step-Up Transformer • Increases voltage • Step-Down Transformer • Decreases voltage
Electrical Transformers • NOT 100% efficient!!! • Not all of the input electrical energy is transferred to electrical energy at the output. • There is some heat generated and also a little bit of sound - transformers get hot and hum!