Electricity and MagnetismElectricity and Magnetism

Chapter 7 Section 1Chapter 7 Section 1

Chapter 8 Sections 2 & 3Chapter 8 Sections 2 & 3

Chapter 7 Section 1Chapter 7 Section 1

Electric ChargeElectric Charge

Positive and Negative ChargePositive and Negative Charge

Atoms have particles ___________________, Atoms have particles ___________________, neutrons, and ___________________neutrons, and ___________________pp++ = _____ charge n = _____ charge noo = no charge e = no charge e-- = ______ = ______ chargechargeSame # of pSame # of p++ and _______ = atoms are and _______ = atoms are electrically neutralelectrically neutral

Transferring ChargeTransferring Charge

Some electrons are bound _____________ to Some electrons are bound _____________ to some objectssome objects

ee-- bound to ______________ more than carpet bound to ______________ more than carpet

Shoe _______________ eShoe _______________ e-- = - charged = - charged

Carpet _____________ eCarpet _____________ e-- = + charged = + charged

Static Electricity: Static Electricity: accumulation of _________ accumulation of _________ electric chargeelectric charge

Conservation of ChargeConservation of Charge

Def:Def: charge can be charge can be _________________ _________________ from object to object, from object to object, but it cannot be but it cannot be _______________ or _______________ or destroyed.destroyed.

Charges Exert ForcesCharges Exert Forces

Clingy clothes from a Clingy clothes from a dryerdryerOpposites _________Opposites _________Force depends on Force depends on _________________ _________________ and size of chargeand size of chargePositive clothes like Positive clothes like ________________ ________________ clothesclothesLike charges repelLike charges repel

Opposite charges attract

Like charges repel

Electric vs. Gravitational ForceElectric vs. Gravitational Force

________________ force from p________________ force from p++ and e and e-- in H in H atom is 10atom is 103939 times stronger than times stronger than _________________________ force_________________________ forceMost things gravity force is stronger than Most things gravity force is stronger than electricalelectrical

Conductors and InsulatorsConductors and Insulators

Conductor:Conductor: material where e material where e-- move move ________________________________________

Metals best conductors – _____________Metals best conductors – _____________

________________________________________ material where e material where e-- do NOT move easilydo NOT move easily

Plastics, wood, rubber, ______________Plastics, wood, rubber, ______________

Charging ObjectsCharging Objects

Rubbing materials can ______________ Rubbing materials can ______________ ee-- - one is (+) the other is (-) - one is (+) the other is (-) charging charging by ______________by ______________

Charge by InductionCharge by Induction

Def:Def: rearrangement of __________________ on rearrangement of __________________ on neutral object by nearby charged object.neutral object by nearby charged object.

LightningLightning

Static ________________: transfer of Static ________________: transfer of charge because of a ________________ charge because of a ________________ of static electricityof static electricity

Clouds have __________________ of air Clouds have __________________ of air and rain and rain areas of + and – charge build areas of + and – charge build

Lightning is _________________ between Lightning is _________________ between cloud and groundcloud and ground

ThunderThunder

Lightning ___________ eLightning ___________ e-- from from atmosphere and produces heat increase atmosphere and produces heat increase ____________________________________

Atoms expand ________________ and Atoms expand ________________ and release sound wavesrelease sound waves

Earth is struck ____________ times every Earth is struck ____________ times every secondsecond

GroundingGrounding

_________________ effects from charge _________________ effects from charge build upbuild upIf there is a ______________ to earth – If there is a ______________ to earth – relieves build uprelieves build upGrounded – it will transfer any Grounded – it will transfer any ________________ charge to earth (big ________________ charge to earth (big neutral object)neutral object)

ElectroscopeElectroscope

Chapter 8 Section 2Chapter 8 Section 2

Electricity and MagnetismElectricity and Magnetism

Basics of MagnetsBasics of Magnets

Magnetic ______________:Magnetic ______________: exerts a exerts a force other magnetic objectsforce other magnetic objects

Magnetic ______________:Magnetic ______________: where where magnetic force is strongestmagnetic force is strongest

Field goes from Field goes from North to _____________North to _____________

Earth’s Magnetic FieldEarth’s Magnetic Field

CompassCompass

Compass needle is small _______________ – Compass needle is small _______________ – lines up with earth’s magnetic fieldlines up with earth’s magnetic field

From From ___________________ ___________________ magnetic magnetic pole to pole to

_________________ _________________ magnetic magnetic polepole

Electric Current and MagnetismElectric Current and Magnetism

_______________ electric currents create _______________ electric currents create magnetic field in direction of currentmagnetic field in direction of current_________________ increases = increase _________________ increases = increase ____________________ field____________________ field

ElectromagnetsElectromagnets

Def:Def: ____________________ magnet ____________________ magnet made by wrapping a ______________ coil made by wrapping a ______________ coil carrying a current around an ___________ carrying a current around an ___________ corecore

Magnetic field in ______________ isMagnetic field in ______________ is

stronger than ________________ wirestronger than ________________ wire

_____________________:_____________________: single wire single wire wrapped in cylindrical coilwrapped in cylindrical coil

ElectromagnetsElectromagnets

______________________________ ______________________________

Properties of ElectromagnetsProperties of Electromagnets

Temporary b/c when _______________Temporary b/c when _______________

stops – _________________ stopsstops – _________________ stops

Increase strength – more ____________Increase strength – more ____________

in solenoid or more ______________in solenoid or more ______________

Useful b/c magnetic strength can be Useful b/c magnetic strength can be __________________ – used for work – __________________ – used for work – motors and speakersmotors and speakers

Making SoundMaking Sound

CD changing CD changing ______________ info ______________ info changing changing ____________ ____________ currentcurrentElectromagnet is Electromagnet is ______________ or ______________ or repelled by repelled by permanent magnetpermanent magnetMoves speaker Moves speaker _____________ to _____________ to make musicmake music

Rotating ElectromagnetsRotating Electromagnets

______________ current to change poles ______________ current to change poles electromagnet ________________ electromagnet ________________

GalvanometersGalvanometers

Def:Def: use electromagnet to measure use electromagnet to measure ____________________ current____________________ current

Used in ______________ in carsUsed in ______________ in cars

Electric MotorsElectric Motors

Def:Def: device that changes _________________ device that changes _________________

energy to ____________________ energyenergy to ____________________ energy

Simple Electric MotorSimple Electric Motor

3 main parts: 3 main parts: wirewire ________________________, , permanentpermanent______________________________________ and and batterybatteryAlso have Also have brushesbrushes – conducting – conducting _____________ connected to battery and a_____________ connected to battery and a commutatorcommutator – ___________ conducting metal – ___________ conducting metal ringring

Spinning MotorSpinning Motor

Commutator _______________ with coil as current runs throughCommutator _______________ with coil as current runs through Step 1:Step 1: Step 2:Step 2:

brushes ____________in brushes ____________in contact with commutator contact with commutator Inertia keeps coil spinningInertia keeps coil spinning

Spinning MotorSpinning Motor

Step 3:Step 3: Step 4:Step 4:

commutator _____________commutator _____________ commutator commutator current – keeps spinning current – keeps spinning reverses current reverses current

again - keepsagain - keeps

spinningspinning

Chapter 8 Section 3Chapter 8 Section 3

Producing Electric CurrentProducing Electric Current

Mechanical to Electrical EnergyMechanical to Electrical Energy

Moving Moving ________________________________ through through

magnetic fieldmagnetic field ______________ current ______________ current

Moving Moving ______________________________ through through wire wire looploop electric current electric current

Electromagnetic induction:Electromagnetic induction: creating a creating a current by _________________ magnetic current by _________________ magnetic fieldfield

GeneratorsGenerators

Def:Def: uses electromagnetic ________________ uses electromagnetic ________________ to transform mechanical energy to to transform mechanical energy to ____________________.____________________.

Move a _____________ in a permanent magnetMove a _____________ in a permanent magnet

Switching Current DirectionsSwitching Current Directions

Each half-turn poles of coil _________________ Each half-turn poles of coil _________________ current switches direction current switches direction

Coil keeps rotating current periodically changes Coil keeps rotating current periodically changes ________________________________________

US generators rotate ____________ times/sec = US generators rotate ____________ times/sec = 3,600 rotations/min3,600 rotations/min

Using GeneratorsUsing Generators

This type of generator is used in cars = This type of generator is used in cars = ________________________________________________

Lights, accessories, spark plugs Lights, accessories, spark plugs

Running _________________ turns coilRunning _________________ turns coil

Electricity to Your HomeElectricity to Your HomeHuge generators in power plants rotate the Huge generators in power plants rotate the permanent ____________________ and the coil permanent ____________________ and the coil stays stillstays stillElectricity is generated in the ______________Electricity is generated in the ______________A A _______________________:_______________________: (large wheel (large wheel rotates when pushed by water, wind or steam) rotates when pushed by water, wind or steam) spins the ____________________spins the ____________________Some use thermal energy – heat water – turn Some use thermal energy – heat water – turn turbine (_____________________ energy) – turbine (_____________________ energy) – spin generator (electrical energy)spin generator (electrical energy)Pg. 241Pg. 241

Direct and Alternating CurrentsDirect and Alternating Currents

Current in ________________ vs. electric Current in ________________ vs. electric generatorgeneratorBattery – Battery – ______________ Current (DC)______________ Current (DC): : flows in one direction through wireflows in one direction through wireWall Outlet – Wall Outlet – Alternating Current (AC)Alternating Current (AC): : _____________________ direction of _____________________ direction of current in a regular patterncurrent in a regular pattern60 cycles/s = 60 ________ 60 cycles/s = 60 ________ changes changes direction ___________ times each seconddirection ___________ times each second

Transmitting Electrical EnergyTransmitting Electrical Energy

Electricity to your houseElectricity to your house

Goes through ______________ lines – Goes through ______________ lines – energy energy heat due to heat due to ____________________ in wires____________________ in wires

Reduce heat/resistance Reduce heat/resistance send at high send at high voltage __________________ Vvoltage __________________ V

BUT can’t use that high of voltage BUT can’t use that high of voltage goes goes through __________________through __________________

TransformersTransformersDef:Def: ___________________ or decreases the ___________________ or decreases the voltage of an alternating current.voltage of an alternating current.Has Has ________________ coil________________ coil and and secondary coilsecondary coil wrapped around same iron corewrapped around same iron coreCurrent goes in primary coil Current goes in primary coil magnetizes core magnetizes coreAs AC current changes direction the As AC current changes direction the _________________ of magnet change_________________ of magnet changeChanging poles Changing poles creates electric current in creates electric current in _____________________ coil_____________________ coil

Types of TransformersTypes of Transformers

____________________________________: increases voltage – : increases voltage – outgoing is higheroutgoing is higherPrimary coil smallerPrimary coil smaller than secondary than secondary__________________:__________________: decreases voltage – decreases voltage – outgoing is loweroutgoing is lowerPrimary coil is largerPrimary coil is larger than secondary than secondary

Transmitting ACTransmitting AC

Generator Generator step-__________ tran. step-__________ tran. high voltage lines high voltage lines step-___________ step-___________ tran. tran. house house