Electricity Electric Charge Electric Charge Static Electricity  Conductors  Insulators  Electroscope  Transferring Charge.

Download Electricity Electric Charge Electric Charge Static Electricity  Conductors  Insulators  Electroscope  Transferring Charge.

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ElectricityElectric Charge Static ElectricityConductorsInsulatorsElectroscopeTransferring ChargeStatic ElectricityStatic Electricitythe net accumulation of electric charges on an objectBehavior of Chargesopposite charges attractlike charges repelStatic ElectricityStatic Dischargethe movement of electrons to relieve a separation in chargeConductorsConductormaterial that allows electrons to move through it easilyex: metals like copper and silverInsulatorsInsulatormaterial that doesnt allow electrons to move through it easilyex: plastic, wood, rubber, glassTransferring ChargeFrictionObjects will either gain or lose e- through friction, acquiring a + or chargeBalloonsSocks on carpetCar in winterDryerTransferring ChargeBy Contact (Conduction)Touching objects can transfer charge by creating a pathway for it to flow from one object to the otherVan De Graaff generatorTransferring ChargeInductionTransfer of charge without contact (objects come close to one another)WallDoorknobVan de GraafElectricityElectric CurrentCircuitPotential DifferenceCurrentResistanceOhms LawCircuitCircuitclosed path through which electrons can flowPotential DifferencePotential Difference (voltage)difference in electrical potential between two places (usually the + and terminals of a battery)measured in volts (V)CurrentCurrentflow of electrons through a conductormeasured in amperes (A)ResistanceResistanceopposition to the flow of electronsmeasured in ohms ()ResistanceResistance depends onthe conductorwire thicknessless resistance in thicker wireswire length less resistance in shorter wirestemp - less resistance at low tempsConcept Check!If we increase resistance, what will happen to the current (flow of electrons)?What about if we decrease resistance?Ohms LawOhms LawV = I RV: potential difference (Volts, V)I: current (Amps, A)R: resistance (Ohms, )If resistance increases, then the current decreases. If voltage increases, then the current increases. Ohms LawA lightbulb with a resistance of 160 is plugged into a 120-V outlet. What is the current flowing through the bulb?Electrical PowerElectrical Powerrate at which electrical energy is converted to another form of energyP = I VP: power (W)I: current (A)V: potential difference (V)Electrical PowerA calculator has a 0.01-A current flowing through it. It operates with a potential difference of 9 V. How much power does it use?ElectricityElectrical CircuitsCircuit componentsSeries circuitsParallel circuitsHousehold circuitsCircuitCircuitclosed path through which electrons can flowCircuit ComponentsA - batteryC - light bulbB - switchD - resistorSeries CircuitsSeries Circuitcurrent travels in a single pathone break stops the flow of currentcurrent is the same throughout circuit lights are equal brightnesseach device receives a fraction of the total voltage get dimmer as lights are addedParallel CircuitsParallel Circuitscurrent travels in multiple pathsone break doesnt stop flowcurrent varies in different branchestakes path of least resistancebigger light would be dimmereach device receives the total voltageno change when lights are addedHousehold CircuitsCombination of parallel circuitstoo many devices can cause wires to overheatSafety Features:fuse - metal melts, breaking circuitcircuit breaker - bimetallic strip bends when hot, breaking circuitMagnetismI. Characteristics of MagnetsMagnetismMagnetic polesMagnetic fieldMagnetic domainA. MagnetismMagnetismforce of attraction or repulsion between unlike or like poles due to the arrangement of electronsclosely related to electricityB. Magnetic PolesMagnetic Poleslike poles repelunlike poles attracta broken magnet creates new polesC. Magnetic FieldMagnetic Fieldarea around a magnet where magnetic forces actfield lines show direction of field (NS)D. Magnetic DomainMagnetic Domaingroups of atoms with aligned magnetic polesin a magnetized object, domains are all aligneddomainMagnetismII. Uses of Magnetic FieldsElectromagnetSpeakerMotorA. ElectromagnetElectromagnetstrong, temporary magnet formed when current is passed through a coil of wire surrounding an iron coreacts like a bar magnet when current is onB. SpeakerSpeakerelectrical energy mechanical energywire coil moves back & forth as its magnetic field interacts with the field of a fixed magnetforced vibration causes the cone to move soundC. MotorMotorelectrical energy mechanical energyelectromagnet rotates between the poles of a fixed magnetcommutator reverses the poles of the emagnetC. MotorMagnetismIII. Producing Electric CurrentElectromagnetic InductionElectric GeneratorDC & ACTransformerA. Electromagnetic InductionElectromagnetic Inductionproducing a current by moving a wire through a magnetic fieldsome microphones work just like mini-speakers in reversesound waves cause coil to move currentB. Electric GeneratorElectric Generatormechanical energy electrical energyarmature is rotated between magnet polesmagnetic field induces a current in the wire coilB. Electric Generator Hydroelectric DamPE of lake water is converted to KEmechanical KE turns the generator shaft which creates electrical energyC. DC & ACDirect Current (DC)current flows in one directiondry cellsAlternating Current (AC)current reverses its direction at regular intervalselectrical outletsD. TransformerTransformerincreases or decreases AC voltage primary coil AC produces a magnetic field that induces AC in the secondary coilvoltage ratio = ratio of turns in each coilD. TransformerStep-up Transformerincreases the voltagemore turnspower plantsStep-down Transformerdecreases the voltagefewer turnshousehold appliances (hairdryers, etc.)11111


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