 Electricity and magnetism are different aspects of a single force: electromagnetism  Electricity = result of charged particles  Magnetism = result of moving electrons in an atom

 Moving electric charge creates a magnetic field.  Magnetic field lines form circles around wire  Right hand rule

 Solenoid – a coil of wire with an electric current (produces magnetic field).  By putting a solenoid around an magnetic metal, you create an electromagnet.

 Strength of electromagnet depends on 1. Current 2. Number of loops 3. Type of core

 Many devices use electromagnets: 1. Galvanometer – device that detects and measures electric current 2. Electric motor – uses an electromagnet to turn an axle. 3. Loudspeaker – uses changing current to move a magnet back and force to produce sound waves

 Moving a magnet into and out of a coil of wire causes charges in a wire to move.  Electromagnetic induction – process of creating a current by changing a magnetic field

 Moving a magnet into and out of a coil of wire causes charges in a wire to move.  Became Faraday’s Law  Obeys conservation of energy

 Generators are the opposite of motors: convert mechanical energy into electrical energy.  Have wire loops that are rotated between two magnets  Can be either AC or DC

 Transformer – device that increases or decreases the voltage of AC.  Consists of two coils of wire wrapped around opposite sides of a closed iron loop  One side has more loops  More loops = greater voltage  Used to transfer electricity (power plant to homes)

 Fold the paper as instructed  Label each section as follows:  For each section, draw the correct figure from the book, including labels and the caption. GalvanometerElectric motorLoudspeaker GeneratorStep-Up Transformer Step-Down Transformer

 Galvanometer: Fig 5 on p. 630 (Fig 10 p. 638)  Electric motor: Fig 6 on p. 631 (Fig 11 p. 639)  Loudspeaker: Speaker pic on p. 635 (none)  Generator: Fig 3 on p. 634 (Fig 14 p. 643)  Step-Up Transformer: Fig 7A on p. 638 (Fig 16B p. 645)  Step-Down Transformer: Fig 7B on p. 638 (Fig 16A p. 645)