Electricity & MagnetismElectricity & Magnetism

Static, Currents, CircuitsStatic, Currents, Circuits

Magnetic Fields & Electro MagnetsMagnetic Fields & Electro Magnets

Motors & GeneratorsMotors & Generators

Atoms…Atoms…

Have Have neutronsneutrons, , protonsprotons, and , and electronselectrons..

Protons are Protons are positivelypositively charged chargedElectrons are Electrons are negativelynegatively charged charged

Electrons…Electrons…

Are located on the Are located on the outerouter edges of edges of atoms…they can be atoms…they can be movedmoved..

A A concentrationconcentration of electrons in an of electrons in an atom creates a net atom creates a net negativenegative charge.charge.

If electrons are If electrons are strippedstripped away, the away, the atom becomes atom becomes positivelypositively charged. charged.

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The world is filled with The world is filled with electrical electrical chargescharges::

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What is this electrical What is this electrical potentialpotential called?called?

Static ElectricityStatic Electricity

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Static ElectricityStatic Electricity

The The build upbuild up of an electric charge of an electric charge on the on the surfacesurface of an object. of an object.

The charge builds up but The charge builds up but does not does not flow.flow.

Static electricity is Static electricity is potential energypotential energy. . It does It does notnot move. It is move. It is storedstored..

When static electricity is When static electricity is dischargeddischarged a “a “sparkspark” or “” or “shockshock” occurs.” occurs.

Static Discharge…Static Discharge…

Occurs when there is a Occurs when there is a lossloss of of static electricity due to three static electricity due to three possible things:possible things:

FrictionFriction - rubbing - rubbingConductionConduction – direct contact – direct contactInductionInduction – through an electrical – through an electrical field (not direct contact)field (not direct contact)

Electricity that Electricity that movesmoves……

Current (electricity)Current (electricity): The flow of : The flow of electrons from one place to electrons from one place to another.another.

Measured in Measured in amperesamperes (amps) (amps)KineticKinetic energy energy

Conductors vs. InsulatorsConductors vs. Insulators

ConductorsConductors – material through which electric – material through which electric current flows current flows easilyeasily..A switch is a conductor that bridges the gap in A switch is a conductor that bridges the gap in

a circuita circuitIt is like a drawbridge-It is like a drawbridge-

When the bridge is down the people can pass- you When the bridge is down the people can pass- you have a have a closed circuitclosed circuit

When the bridge is up no one can pass- you have When the bridge is up no one can pass- you have an an open circuitopen circuit

InsulatorsInsulators – materials through which electric – materials through which electric current current cannot movecannot move..

ExamplesExamples

ConductorsConductors::MetalMetalWater (only Water (only

because of the because of the minerals and minerals and metals in the metals in the water)water)

InsulatorsInsulators::StyrofoamStyrofoamRubberRubberPlasticPlasticPaperPaperWood Wood

What is Resistance?What is Resistance?

The The oppositionopposition to the flow of an to the flow of an electric current, producing electric current, producing heatheat..

The The greatergreater the resistance, the the resistance, the lessless current gets through. current gets through.

GoodGood conductors have conductors have lowlow resistance.resistance.

Measured in Measured in ohms.ohms.

How can we How can we controlcontrol currents? currents?

With With circuitscircuits..CircuitCircuit: is a : is a pathpath for the flow of for the flow of

electrons. We use electrons. We use wireswires..

There are 2 types of circuits:There are 2 types of circuits:

Series CircuitSeries Circuit: the components : the components are lined up along are lined up along oneone path. If path. If the circuit is broken, the circuit is broken, all all components turn off.components turn off.

Series CircuitSeries Circuit

There are 2 types of circuits:There are 2 types of circuits:

Parallel CircuitParallel Circuit – there are – there are severalseveral branching paths to the branching paths to the components. If the circuit is components. If the circuit is broken at any one branch, broken at any one branch, only only the components on that branch the components on that branch will turn offwill turn off..

Parallel CircuitParallel Circuit

How do we Measure Electricity?How do we Measure Electricity?

VoltVolt– the measurement of the amount – the measurement of the amount of electrical push or force in a circuitof electrical push or force in a circuit

WattWatt– the measurement of power, or – the measurement of power, or how fast work is donehow fast work is done

AmpereAmpere– a unit used to measure how – a unit used to measure how much current flows through a given much current flows through a given part of a circuit in one secondpart of a circuit in one second

What is Voltage?What is Voltage?

The The measure of energymeasure of energy given to given to the charge flowing in a circuit.the charge flowing in a circuit.

The The greatergreater the voltage, the the voltage, the greater the force or “pressure”greater the force or “pressure” that drives the charge through the that drives the charge through the circuit.circuit.

Difference b/t Volts and AmpsDifference b/t Volts and Amps

Example – you could say that…Example – you could say that…AmpsAmps measure measure how muchhow much water water

comes out of a hose.comes out of a hose.VoltsVolts measure measure how hardhow hard the water the water

comes out of a hose.comes out of a hose.

Batteries Batteries

Batteries Batteries contain one or morecontain one or more electric cells electric cellsElectric cell- Electric cell- a wire connects 2 metals that a wire connects 2 metals that

are in contact with an are in contact with an electrolyte, electrolyte, it uses it uses chemical energy to produce an electrical chemical energy to produce an electrical currentcurrentElectrolyte-Electrolyte- a liquid or paste substance that a liquid or paste substance that

conducts electricityconducts electricity

BatteriesBatteries

Wet Cell- Wet Cell- uses a uses a liquidliquid electrolyte to conduct electrolyte to conduct electricityelectricity

Dry Cell- Dry Cell- uses a uses a pastepaste electrolyte to conduct electrolyte to conduct electricityelectricity

When a battery is “When a battery is “deaddead” it is because the metal ” it is because the metal in the battery no longer reacts with the in the battery no longer reacts with the electrolyte.electrolyte. The electrolyte may be depletedThe electrolyte may be depleted

oror

The metal is used upThe metal is used up

MagnetismMagnetismMagnetic AttractionMagnetic Attraction- magnetic force, like - magnetic force, like

charges repel, opposites attractcharges repel, opposites attract

Magnetic Field- Magnetic Field- the area surround the magnet the area surround the magnet where the magnet’s force is expressedwhere the magnet’s force is expressedStrongest at the polesStrongest at the poles

Electricity and MagnetismElectricity and Magnetism

These are very closely relatedThese are very closely relatedLike charges repelLike charges repelOpposites attractOpposites attract

The flow of electricity can produce a The flow of electricity can produce a magnet, and a magnet can produce magnet, and a magnet can produce electricityelectricity

What is an electromagnet?What is an electromagnet?

ElectromagnetElectromagnet – a magnet made – a magnet made from a from a coil coil of wire wrapped of wire wrapped around an around an iron or steel core iron or steel core that that is attached to a electrical sourceis attached to a electrical source..

What is a generator?What is a generator?

GeneratorGenerator – a machine that – a machine that changes changes mechanicalmechanical energy to energy to electricalelectrical energy energy

Usually use Usually use movingmoving magnets to magnets to create create currentscurrents in coils of wire. in coils of wire.

What is a motor?What is a motor?

MotorMotor – a device that changes – a device that changes electrical electrical energy to energy to mechanical mechanical energy that can do energy that can do workwork..

ElectronicsElectronics

Electronic Device- Electronic Device- an object that uses an object that uses electricity to communicate information.electricity to communicate information.Electronic devices use an Electronic devices use an electrical signal electrical signal

which is an electrical current that carries which is an electrical current that carries informationinformationTV, Cell phone, iPod….. EtcTV, Cell phone, iPod….. Etc

These electronic devices use a These electronic devices use a binary number binary number system (BNS) system (BNS) to communicateto communicateBNS-BNS- a code using a series of numbers a code using a series of numbers

0 is an open circuit, 1 is a closed circuit0 is an open circuit, 1 is a closed circuit

Integrated CircuitsIntegrated Circuits

Integrated Circuit- Integrated Circuit- a computer chip or a computer chip or microchip, a small circuit with all the parts microchip, a small circuit with all the parts built into it.built into it.

Semi-conductorSemi-conductor- a material that somewhat - a material that somewhat conducts electricity, conducts better than conducts electricity, conducts better than an insulator but not as well as a conductoran insulator but not as well as a conductorActs similar to a switch can act like a Acts similar to a switch can act like a

conductor, closed circuit and or resistorconductor, closed circuit and or resistorsiliconsilicon

Computer PartsComputer Parts

CPU-CPU- central processing unit, it is the brain central processing unit, it is the brain of the computer, it tell the rest of the of the computer, it tell the rest of the computer what to docomputer what to do

ROM-ROM- read only memory- built in memory read only memory- built in memory and programs- it is the instructionsand programs- it is the instructions

RAM-RAM- random access memory- store random access memory- store information temporarilyinformation temporarily

That’s It !!!!That’s It !!!!