static electricity

STATIC STATIC ELECTRICITYELECTRICITY

THE STUDY OF THE STUDY OF CHARGES AT RESTCHARGES AT REST

ACTIVITYACTIVITY

MODEL OF AN ATOMMODEL OF AN ATOM

CHARGE A BALLOONCHARGE A BALLOON

STATIC ELECTRICITYSTATIC ELECTRICITY

When you rub a balloon on your hair you When you rub a balloon on your hair you scrape electrons off the atoms of your hair scrape electrons off the atoms of your hair onto the balloon.onto the balloon.

The atoms of the balloon apparently have The atoms of the balloon apparently have more “grab” on electrons.more “grab” on electrons.

““Laws of Attraction”Laws of Attraction”

Opposite Charges AttractOpposite Charges Attract

Like Charges RepelLike Charges Repel

+ -

+ +

ACTIVITYACTIVITY

STYROFOAM STYROFOAM ELECTROSCOPEELECTROSCOPE

A COULOMBA COULOMB

THE FUNDAMENTAL UNIT THE FUNDAMENTAL UNIT OF CHARGEOF CHARGE

IT IS EQUAL TO THE IT IS EQUAL TO THE CHARGE OF 6.25 BILLION CHARGE OF 6.25 BILLION BILLION ELECTRONSBILLION ELECTRONS

COULOMBS LAWCOULOMBS LAW

ELECTRICAL FORCE ELECTRICAL FORCE DEPENDS ON THE SIZE DEPENDS ON THE SIZE OF THE CHARGES AND OF THE CHARGES AND

THE DISTANCE THE DISTANCE BETWEEN THE CHARGESBETWEEN THE CHARGES

Coulomb’s LawCoulomb’s Law

The force between charges varies The force between charges varies inversely with the square of their inversely with the square of their separation distances.separation distances.

+ +

+ +

COULOMB’S LAWCOULOMB’S LAW

F = k X QF = k X Q11 X Q X Q22 / D / D22

ACTIVITYACTIVITY

POLARIZING A STICKPOLARIZING A STICK

PolarizationPolarization

Polarized objects have an uneven Polarized objects have an uneven distribution of charge.distribution of charge.

A polarized object has no net charge.A polarized object has no net charge.

+ + + + + + + + + + + + + + + + + + + +

- - - - - - - - - - - - - - - - - - - - -

Meter Stick

+ + + + + + + + + + + + + + + + + + + +

- - - - - - - - - - - - - - - - - - - - -

- -

- -

- -

Strong Force

Weak Force

CURRENT CURRENT ELECTRICITYELECTRICITY

THE STUDY OF THE STUDY OF CHARGES IN CHARGES IN

MOTIONMOTION

ELECTRICAL CIRCUITELECTRICAL CIRCUIT

A COMPLETE PATH A COMPLETE PATH FOR ELECTRON FOR ELECTRON

FLOWFLOW

ACTIVITYACTIVITY

ELECTICAL ALTERNATIVESELECTICAL ALTERNATIVES

XMAS TREE BULBXMAS TREE BULB

MAKE A WIREMAKE A WIRE

CIRCUIT WIRECIRCUIT WIRE

CONDUCTORCONDUCTOR

INSULATOR

ELECTRICAL CIRCUITELECTRICAL CIRCUITCONSISTS OFCONSISTS OF

•SOURCES OF ELECTRICAL ENERGY

•A COMPLETE CONDUCTING PATH

•DEVICES THAT CONVERT ELECTRICAL ENERGY TO OTHER FORMS

ACTIVITYACTIVITY

ADDING BATTERIESADDING BATTERIES

MAKE A SWITCHMAKE A SWITCH

What is a conductor?What is a conductor?

a material that allows free electron a material that allows free electron movementmovement

Examples:Examples: AluminumAluminum GoldGold CopperCopper All MetalsAll Metals

ACTIVITYACTIVITY

GOOD CONDUCTORSGOOD CONDUCTORS

POOR CONDUCTORSPOOR CONDUCTORS

What is an insulator?What is an insulator?

a material that does not allow electrons a material that does not allow electrons to flow freelyto flow freely

Examples:Examples: PlasticsPlastics CeramicsCeramics AmberAmber

ACTIVITYACTIVITY

CONDUCTIVITY CONDUCTIVITY TESTERTESTER

LIGHT BULBLIGHT BULB

FILAMENTFILAMENT

CONDUCTOR

ACTIVITYACTIVITY

CREATING LIGHTCREATING LIGHT

BATTERIESBATTERIES

1.5 VOLTS1.5 VOLTS

STANDARD “D” CELL

+ TERMINAL- TERMINAL

VOLTAGEVOLTAGE

COMMON TERM FOR COMMON TERM FOR “POTENTIAL”“POTENTIAL”

THE AMOUNT OF ENERGY PER THE AMOUNT OF ENERGY PER ELECTRON PRODUCED BY AN ELECTRON PRODUCED BY AN ENERGY SOURCE (BATTERY)ENERGY SOURCE (BATTERY)

ELECTRICAL ELECTRICAL CURRENTCURRENT

THE RATE OF FLOW OF THE RATE OF FLOW OF CHARGECHARGE

ELECTRICAL CURRENTELECTRICAL CURRENT

THE BRIGHTNESS OF A LIGHT BULB IS THE BRIGHTNESS OF A LIGHT BULB IS A GOOD INDICATOR OF THE RELATIVE A GOOD INDICATOR OF THE RELATIVE AMOUNT OF CURRENT FLOWING AMOUNT OF CURRENT FLOWING THROUGH IT.THROUGH IT.


ELECTRONS FLOW OUT OF THE ELECTRONS FLOW OUT OF THE NEGATIVE TERMINAL OF A BATTERY.NEGATIVE TERMINAL OF A BATTERY.

AFTER ELECTRONS TRAVEL AFTER ELECTRONS TRAVEL THROUGH THE CIRCUIT, THEY FLOW THROUGH THE CIRCUIT, THEY FLOW INTO THE POSITIVE TERMINAL OF THE INTO THE POSITIVE TERMINAL OF THE BATTERY.BATTERY.

ELECTRICAL ELECTRICAL RESISTANCERESISTANCE

RESISTANCE TO ELECTRON RESISTANCE TO ELECTRON FLOWFLOW

ACTIVITYACTIVITY

PENCIL LEAD DIMMER PENCIL LEAD DIMMER SWITCHSWITCH

LIGHT DIMMERLIGHT DIMMER

ELECTRICAL SHORTELECTRICAL SHORT

A LOW RESISTANCE PATH ACROSS A LOW RESISTANCE PATH ACROSS THE TERMINALS OF AN ELECTRICAL THE TERMINALS OF AN ELECTRICAL CIRCUIT ELEMENT.CIRCUIT ELEMENT.

IF IT OCCURS ACROSS A BATTERY, IF IT OCCURS ACROSS A BATTERY, GENERATOR OR ANY ENERGY GENERATOR OR ANY ENERGY SOURCE, IT CAN CAUSE TOO HIGH OF SOURCE, IT CAN CAUSE TOO HIGH OF A CURRENT.A CURRENT.

ELECTRICAL SHORTELECTRICAL SHORT

SOMETIMES A RESISTOR CAN HAVE A SOMETIMES A RESISTOR CAN HAVE A SHORT ACROSS ITS LEADS. IF THIS SHORT ACROSS ITS LEADS. IF THIS OCCURS AND ANOTHER RESISTOR IS OCCURS AND ANOTHER RESISTOR IS IN THE CIRCUIT, THE OTHER IN THE CIRCUIT, THE OTHER RESISTOR MAY POSSESS ENOUGH RESISTOR MAY POSSESS ENOUGH RESISTANCE TO KEEP THE CURRENT RESISTANCE TO KEEP THE CURRENT FROM BECOMING TOO LARGE. WHEN FROM BECOMING TOO LARGE. WHEN THIS OCCURS, NO CURRENT WILL THIS OCCURS, NO CURRENT WILL PASS THROUGH THE SHORTED PASS THROUGH THE SHORTED RESISTOR.RESISTOR.

CIRCUIT DIAGRAMCIRCUIT DIAGRAMA CONCISE REPRESENTATION A CONCISE REPRESENTATION OF AN ELECTRICAL CIRCUIT OF AN ELECTRICAL CIRCUIT UTILIZING STANDARD UTILIZING STANDARD ELECTRICAL SYMBOLS.ELECTRICAL SYMBOLS.

IT SHOULD BE ACCURATE, IT SHOULD BE ACCURATE, SIMPLE AND NEAT.SIMPLE AND NEAT.

ACTIVITYACTIVITY

ELECTROSQUARESELECTROSQUARES

DRAWING CIRCUITSDRAWING CIRCUITS

ELECTRON CURRENTELECTRON CURRENT

A MEASURE OF THE RATE OF FLOW A MEASURE OF THE RATE OF FLOW OF ELECTRON CHARGE THROUGH A OF ELECTRON CHARGE THROUGH A CIRCUIT.CIRCUIT.

THE DIRECTION OF FLOW IS FROM THE DIRECTION OF FLOW IS FROM THE NEGATIVE SIDE OF THE ENERGY THE NEGATIVE SIDE OF THE ENERGY SOURCE THROUGH THE CIRCUIT TO SOURCE THROUGH THE CIRCUIT TO THE POSITIVE SIDE OF THE ENERGY THE POSITIVE SIDE OF THE ENERGY SOURCE.SOURCE.

OHM’S LAWOHM’S LAWTHE CURRENT THROUGH A RESISTOR THE CURRENT THROUGH A RESISTOR

IS PROPORTIONAL TO THE APPLIED IS PROPORTIONAL TO THE APPLIED VOLTAGE AND INVERSELY VOLTAGE AND INVERSELY PROPORTIONAL TO ITS RESISTANCE.PROPORTIONAL TO ITS RESISTANCE.

I = V / RI = CURRENTV = VOLTAGER = RESISTANCE


• A MEASURE OF THE NUMBER OF A MEASURE OF THE NUMBER OF COULOMBS PER SECOND THAT COULOMBS PER SECOND THAT PASSES A POINT IN A CIRCUIT.PASSES A POINT IN A CIRCUIT.

• THE UNIT OF CURRENT IS THE THE UNIT OF CURRENT IS THE

AMPERE = COULOMB PER SECONDAMPERE = COULOMB PER SECOND

VOLTAGE (POTENTIAL)VOLTAGE (POTENTIAL)

THE ENERGY PER CHARGE LOST OR THE ENERGY PER CHARGE LOST OR GAINED BY CHARGES AS THEY PASS GAINED BY CHARGES AS THEY PASS THROUGH A DEVICE.THROUGH A DEVICE.

THE UNIT IS THETHE UNIT IS THE

VOLT = JOULE PER COULOMBVOLT = JOULE PER COULOMB

RESISTANCERESISTANCEA MEASURE OF THE RESISTANCE A MEASURE OF THE RESISTANCE TO ELECTRON FLOW.TO ELECTRON FLOW.

THE UNIT IS THE THE UNIT IS THE

OHM = VOLT PER AMPEREOHM = VOLT PER AMPERE

SYMBOL FOR OHM IS SYMBOL FOR OHM IS

RESISTANCERESISTANCE

RESISTANCE CAN BE RELATED TO RESISTANCE CAN BE RELATED TO THE AMOUNT OF VOLTAGE NEEDED THE AMOUNT OF VOLTAGE NEEDED TO PRODUCE A AMPERE OF TO PRODUCE A AMPERE OF CURRENT.CURRENT.

IF IT TAKES TWO VOLTS TO PRODUCE IF IT TAKES TWO VOLTS TO PRODUCE ONE AMPERE, THE RESISTANCE IS ONE AMPERE, THE RESISTANCE IS TWO OHMS TWO OHMS

Current, Voltage, ResistanceCurrent, Voltage, Resistance

CurrentCurrent a measure of the rate of flow of electronsa measure of the rate of flow of electrons measures in Amperes (A)measures in Amperes (A)

VoltageVoltage a measure of the energy per charge a measure of the energy per charge measured in Volts (V)measured in Volts (V)

ResistanceResistance a measure of the resistance to electron flowa measure of the resistance to electron flow measured in Ohms (measured in Ohms ())

SERIES CIRCUITSSERIES CIRCUITS

THE CURRENT HAS A THE CURRENT HAS A SINGLE PATH SINGLE PATH AROUND THE AROUND THE

CIRCUITCIRCUIT

ACTIVITYACTIVITY

SERIES CIRCUITSERIES CIRCUIT

CIRCUIT ELEMENTS CIRCUIT ELEMENTS IN SERIESIN SERIES

ALL HAVE THE SAME ALL HAVE THE SAME CURRENT CURRENT

THROUGH THEMTHROUGH THEM

PARALLEL CIRCUITPARALLEL CIRCUIT

THE CURRENT HAS THE CURRENT HAS MULTIPLE PATHS MULTIPLE PATHS

AROUND THE AROUND THE CIRCUITCIRCUIT

ACTIVITYACTIVITY

PARALLEL CIRCUITSPARALLEL CIRCUITS

CIRCUIT ELEMENTS CIRCUIT ELEMENTS IN PARALLELIN PARALLEL

ALL HAVE THE SAME ALL HAVE THE SAME VOLTAGE ACROSS VOLTAGE ACROSS

THEM THEM

RESISTORS IN SERIESRESISTORS IN SERIES

THE TOTAL RESISTANCE THE TOTAL RESISTANCE IS THE SUM OF ALL IS THE SUM OF ALL RESISTORS IN SERIES.RESISTORS IN SERIES.

RESISTORS IN PARALLELRESISTORS IN PARALLEL

THIS COMBINATION THIS COMBINATION POSSESSES LESS COMBINED POSSESSES LESS COMBINED RESISTANCE THAN THE RESISTANCE THAN THE LOWEST RESISTOR IN THE LOWEST RESISTOR IN THE COMBINATION.COMBINATION.

BATTERIES IN SERIESBATTERIES IN SERIES

THE TOTAL VOLTAGE THE TOTAL VOLTAGE PRODUCED BY BATTERIES IN PRODUCED BY BATTERIES IN SERIES IS THE SUM OF THE SERIES IS THE SUM OF THE VOLTAGES OF EACH BATTERYVOLTAGES OF EACH BATTERY

BATTERIES IN PARALLELBATTERIES IN PARALLEL

PRODUCE THE SAME PRODUCE THE SAME VOLTAGEVOLTAGE

QUESTIONQUESTION

HOW DO YOU CONNECT A BATTERY TO HOW DO YOU CONNECT A BATTERY TO “JUMP START” YOU CAR?“JUMP START” YOU CAR?

WHY ARE BATTERIES CONNECTED IN WHY ARE BATTERIES CONNECTED IN BOTH PARALLEL AND SERIES IN SOME BOTH PARALLEL AND SERIES IN SOME

PORTABLE DEVICES?PORTABLE DEVICES?

ACTIVITYACTIVITY

ELECTRIC CIRCUITSELECTRIC CIRCUITS

DIODEDIODE

DIODE MEANS TO CONDUCT IN DIODE MEANS TO CONDUCT IN ONLY ONE DIRECTION ONLY ONE DIRECTION

WILL NOT CONDUCT ELECTRONS

WILL CONDUCT ELECTRONS

LIGHT EMITTING DIODE (LED)LIGHT EMITTING DIODE (LED)

A DIODE THAT EMITS LIGHT A DIODE THAT EMITS LIGHT WHEN CURRENT IS PRESENT.WHEN CURRENT IS PRESENT.

MOST LED’S REQUIRE ONLY A MOST LED’S REQUIRE ONLY A MILLIAMP TO BE SEEN.MILLIAMP TO BE SEEN.

FUSEFUSE

A FUSE IS PLACED IN SERIES A FUSE IS PLACED IN SERIES WITH THE ENERGY SOURCE. WITH THE ENERGY SOURCE. IT IS RATED TO BURN (OR IT IS RATED TO BURN (OR MELT) IF THE CURRENT MELT) IF THE CURRENT THROUGH IT EXCEEDS ITS THROUGH IT EXCEEDS ITS RATING.RATING.

ACTIVITYACTIVITY

CIRCUIT BREAKERSCIRCUIT BREAKERS

CIRCUIT BREAKERCIRCUIT BREAKER

A MAGNETIC SWITCH THAT A MAGNETIC SWITCH THAT BREAKS THE CIRCUIT IF BREAKS THE CIRCUIT IF THE CURRENT IN THE THE CURRENT IN THE CIRCUIT EXCEEDS ITS CIRCUIT EXCEEDS ITS RATINGRATING

SWITCHESSWITCHES

SINGLE POLE SINGLE THROWSINGLE POLE SINGLE THROW

SINGLE POLE DOUBLE THROW

ACTIVITYACTIVITY

MAKE A SWITCHMAKE A SWITCH

LEMON BATTERYLEMON BATTERY

THE ZINC TERMINAL IS NEGATIVETHE ZINC TERMINAL IS NEGATIVE

THE COPPER TERMINAL IS POSITIVETHE COPPER TERMINAL IS POSITIVE

ABOUT 1 VOLT IS PRODUCED BY A SINGLE ABOUT 1 VOLT IS PRODUCED BY A SINGLE LEMON BATTERYLEMON BATTERY

YOU NEED TWO LEMONS TO LIGHT AN LEDYOU NEED TWO LEMONS TO LIGHT AN LED

ACTIVITYACTIVITY

LIGHT AN LED USING LIGHT AN LED USING LEMON BATTERIESLEMON BATTERIES

static electricity

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