Physics Electricity & Magnetism

What is static electricity?


A buildup of charge where electrons move between materials and jump back to a positive surface.

Static Electricity: Def 


is the result of the imbalance of electrons on a surface

Magectic

• all magnets have a south and north pole

• opposite poles attract each other

• same poles repel each other

• permanent magnets have a permanent magnetic field surrounding them

• field lines show the direction of the force at any point on an imaginary single north pole that is placed near the magnet

DC

Direct current the electrons always travel in the same direction

Examples:

Electronics (Computers, phones, etc) use DC

AC

Alternating current the direction the electrons travel alternates direction 50 times every second

Examples:

Household appliances (Fridges, toasters, kettles) use AC

electromagnets

a current carrying wire produces its own magnetic field - called electromagnetism

• if you place a compass near a current carrying wire, it will line up with the electric field

• no current = no electric field

• current flowing = coil has a magnetic field similar to that of a bar magnet

Electromagnets How its created

created by moving electric charges — electric currents produce magnetic fields, and changing magnetic fields induce electric fields.

generators

• a device that converts movement energy into electricity

• generators are found in steam turbines, gas turbines, water turbines

A Basic Generator has

1. a wire loop, being rotated

2. a permanent magnet

3. a slip ring communicator

• rotating the wire inside a magnetic field induces a current in the wire

• generators use kinetic energy to create electrical energy

fuses

High Resistance wires that have a low melting point. The wire will melt if to much current flows, breaking the circuit.

Circuit Breakers

A switch that flips to break the circuit if to much current is flowing through a circuit

Safety Switch

A device that shuts off the supply to a circuit when a different current is measured on the active and neutral lines.