magnets and magnetic fields
DESCRIPTION
Magnets and Magnetic Fields. Ch 21.1. Magnetic Forces. The force a magnet exerts on Another magnet Iron or similar metal Moving charges Magnetic Fields Region where force is strongest North and South. Magnetic Fields. Surrounds a magnet and exerts a magnetic force - PowerPoint PPT PresentationTRANSCRIPT
MAGNETS AND MAGNETIC FIELDSCh 21.1
True False Statement True False
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
MAGNETIC FORCES The force a magnet exerts on
Another magnet Iron or similar metal Moving charges
Magnetic Fields Region where force is strongest North and South
MAGNETIC FIELDS Surrounds a magnet and exerts a magnetic
force
Strongest near the poles Attracts or repels other magnets
MAGNETIC FIELDS
Earth is giant magnet Magnetosphere
Around Magnets Around Earth
MAGNETIC MATERIALS Magnetic Domains
Large # of atoms Aligned magnetic fields
Ferromagnetic Materials Can be magnetized due to domains
MAGNETIC MATERIALS
Domains arranged randomly
Domains arranged in an order
Nonmagnetized Magnetized
ELECTROMAGNETISM Ch. 21.2
True False Statement True False
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
ELECTRICITY AND MAGNETISM Electromagnetic Force
Electric force = charged particles Magnetic force = movement of electrons
ELECTRICITY AND MAGNETISM
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
SOLENOIDS AND ELECTROMAGNETS 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
ELECTROMAGNETIC DEVICES Change electrical
energy into mechanical energy
1. Galvanometer Uses solenoid
2. Electric Motors Uses electromagnets
3. Loudspeakers Uses solenoid
ELECTRICAL ENERGY GENERATION AND TRANSMISSIONCh 21.3
True False Statement True False
Electromagnetic induction is the process of generating voltage by moving an electrical conductor
relative to a magnetic fieldThere 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
GENERATING ELECTRIC CURRENT 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
GENERATOR Device converts mechanical energy into
electrical by rotating a coil of wire in a magnetic field
GENERATORS
Produces alternating current
Produces direct current
AC DC
TRANSFORMERS 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
TRANSFORMERS
Decreases voltage and current
Increases voltage Decreases current
Step Down Step Up
ENERGY IN YOUR HOME Generated by coal,
water, nuclear, wind natural gas, and petroleum
Turbines Fanlike blades that
turn when pushed