M AGNETS AND M AGNETIC F IELDS Ch 21.1

TrueFalseStatementTrueFalse South poles attract North poles, and the same poles repel The Earth is a giant magnet surrounded by a magnetic field called the magnetosphere A ferromagnetic material is always magnetic Nonmagnetized materials have domains that are neatly arranged Magnetized materials have domains that are randomly arranged

M AGNETIC F ORCES The force a magnet exerts on Another magnet Iron or similar metal Moving charges Magnetic Fields Region where force is strongest North and South

M AGNETIC F IELDS Surrounds a magnet and exerts a magnetic force Strongest near the poles Attracts or repels other magnets

M AGNETIC F IELDS Earth is giant magnet Magnetosphere Around MagnetsAround Earth

M AGNETIC M ATERIALS Magnetic Domains Large # of atoms Aligned magnetic fields Ferromagnetic Materials Can be magnetized due to domains

M AGNETIC M ATERIALS Domains arranged randomly Domains arranged in an order NonmagnetizedMagnetized

E LECTROMAGNETISM Ch. 21.2

TrueFalseStatementTrueFalse Moving electric charges creates a magnetic field Solenoids produce magnetic fields by vibrating in place Electromagnets are solenoids with ferromagnetic cores Electric motors use magnets to turn an axle Electromagnetic forces are caused by electric charges

E LECTRICITY AND M AGNETISM Electromagnetic Force Electric force = charged particles Magnetic force = movement of electrons

E LECTRICITY AND M AGNETISM Moving electric fields create a magnetic fields Charge will be deflected in a direction perpendicular to the magnetic field and velocity of charge MF Around Moving Charges Forces Acting on Moving Charges

S OLENOIDS AND E LECTROMAGNETS Solenoid Coil of current carrying wire that produces a magnetic field Electromagnet Solenoid with a ferromagnetic core Changing the current in an electromagnet controls the strength and direction of its magnetic field

E LECTROMAGNETIC D EVICES Change electrical energy into mechanical energy 1. Galvanometer Uses solenoid 2. Electric Motors Uses electromagnets 3. Loudspeakers Uses solenoid

E LECTRICAL E NERGY G ENERATION AND T RANSMISSION Ch 21.3

TrueFalseStatementTrueFalse Electromagnetic induction is the process of generating voltage by moving an electrical conductor relative to a magnetic field There are AC and DC generators that convert electrical energy into mechanical Transformers increase or decrease voltage and current of linked AC circuits Turbines have blades that turn when pushed, helping generate electricity Faraday said current is induced in a conductor by changing the magnetic field

G ENERATING E LECTRIC C URRENT Electromagnetic Induction Generating current by moving an electrical conductor relative to a magnetic field Discovered by Faraday Voltage is induced in a conductor by a changing magnetic field

G ENERATOR Device converts mechanical energy into electrical by rotating a coil of wire in a magnetic field

G ENERATORS Produces alternating current Produces direct current ACDC

T RANSFORMERS Device that increases or decreases voltage and current of 2 linked AC circuits Changes the magnetic field in 1 coil then induces an AC current in a nearby coil with a different # of turns

T RANSFORMERS Decreases voltage and current Increases voltage Decreases current Step DownStep Up

E NERGY IN YOUR H OME Generated by coal, water, nuclear, wind natural gas, and petroleum Turbines Fanlike blades that turn when pushed