Electricity
1.1 Materials can become electrically charged.
Electric charge is a property of matter
Electric charge: a property that allows an object to excert an electric force on another object without touching it
Electric Field: The space around a particle thorugh which an electric charge can excert the force
Charges are caused by the movement of electrons
Static Charge: a buildup of electric charge in an object caused by the presense of of many particles of the same charge
Charging by Contact: when 2 uncharged objects of certain materials touch eachother electrons move from one material to the other it transfers electrons
Charging by Induction: One -ve charged object and one uncharged object come close to eachother there is a transfer of electrons
Iduction: the buildup of a charge without direct contact
Charge Polarization: When a -ve charged object comes near a neutral object, the electrons in the uncharged onject repel and the positive charges attract
Technology uses static electricity
Making cars, copy machines etc.
Charges can move from one place to another
Static charges have potential energy
Electric Potential Energy:
Electric potential
Measured in Volts
Charge Movement: For charge movement, there must be a path for the charge to follow, and there must be a large enough difference in electric potential.
Lightning: when there is a big buildup of electrons in the sky, then they must discharge onto the protons on the ground.
Materials affect charge movement
Conductors and Insulators
Conductor: allows electric charge to pass through (good at conducting energy)
Insulators: don't allow electric charge to pass through (bad at conducting)
Resistance: the property that determines how easily a charge can move through it.
Measured in Ohms (omega symbol)
Super conductors: Really good at conducting energy
Grounding: providing a harmless, low-resistance path a ground for electricity to follow
Electric Current is a flow of charge
Electric charge can flow continuously
Electric Current: A flow of charge
Current, Voltage, and Resistance
Current: ampere (amps)
Ohm's Law
Current=Voltage/Resistance
Electric cells supply electric current
Electric cell: produces elecric current using the chemical or physical properties of different materials
Primary Cells: produces current through chemical reactions flow only goes 1 direction. (can't reuse current)
Storage cells: Produces current through chemical reactions, flow of electrons can be reversed and can go both directions. (can be stored and used later)