Lesson 9: Magnetism & Electricity Pg CRCT coach

Magnetic Force Electricity and magnetism can be used to produce each other Magnetic force: invisible force (push or pull) magnets have on each other Magnets have 2 poles; north and south If you cut a magnet in half you will get two magnets, each with a north and south pole Attract: come together (opposite poles) Repel: push apart (like poles) Magnetic force is strongest at either pole and weaker in the center of a bar magnet Magnetic field: the area around a magnet where magnetic force is exerted Earth is a giant magnet with magnetic north and south poles. Our magnetic poles protect us from harmful particles from the sun

Electric Force Electrical energy: electricity (moving electrons) Static electricity: build up of charges on an object. Like charges repel, opposites attract Electric force: the force between electrically charged objects Electric field: an invisible area around an object where an electric force (push or pull) is felt. Static discharge: releasing a static charge (electrons)when statically charged objects touch electrons move from negatively charged object to positively charged object Ex: lightning/doorknob Electric current: the continuous flow of electrons from a negatively charged object to a positively charged object (like a current in the river) A current won’t move without a circuit (pathway, road, etc)

Electricity and Magnetism Electromagnetism: when current electricity flows through a wire, a magnetic field is formed all around the wire as long as the electricity flows. If the electricity is turned off the magnetic field disappears Electromagnet: a temporary magnet formed by running current through a wire wrapped around a magnetic metal post (iron nail) Can be turned on and off Can be made stronger by Adding more coils of wire Using a bigger magnetic core Adding more current Electromagnetic induction: you can make electricity by rubbing wire across a magnet or rubbing a magnet across wire