2.2

II. Electric Charge A. Electric devices need electric charges that flow constantly. i. they require electronic current 1.the continuous flow of electric charges through a material. i. amount of charges that passes through the wire in a unit of time is the rate. ii. unit-ampere- amp A iii. # of amps describes the amount of charges flowing past a given point each second. 2. current in a circuit i. requires specific path to follow. ii. charges must flow continuously from 1 place to another. iii. requires electric circuit a)complete, unbroken path through which electric charges can flow. b)if complete-charges can flow continuously. c)if broken-charges will not flow. B. Conductors and insulators 1. conductors - transfers electric charge well i. material through which charge can flow easily ii. electrons bound loosely. iii. conduction electrons- are able to move throughout the conductor. as they flow they form electric current iv. used to carry electric charge v. silver, copper, aluminum, iron. 2.Insulators- a material which charge cannot flow easily. i. electrons bound tightly to their atoms. ii. do not move easily ii. ex-rubber coating non an appliance cord. iv. used to stop flow of charges v. rubber, glass, sand, plastic, wood C. voltage 1. potential energy is the energy an object has a result of its position - or height i. higher up- more potential energy. 2. charges in an electric circuit flow because a difference in electrical potential energy between two places in a circuit i potential difference ii. unit of measure the -volt V iii. cause a current in a electric current iv. amount of force pushing an electric current. 4. Voltage source-device that create a potential difference in an electric circuit. i electric circuit requires a source of energy to maintain a voltage ii. battery or generator- turbine, outlets iii. has 2 terminals. iv. voltage between the terminal causes charges to move around a circuit D. resistance 1. current depends on the resistance of material 2.resiatnce- measure of how difficult it is for charges to flow through a material. 3. greater resistance, less current there is for given voltage. 4. unit of measure - ohm i. George ohm ii. German physicist. 5. 4 factors determine resistance of wire or object. i. material from which the wire is made. ii. length. a)longer wires have more resistance iii. diameter a)thin wires have more resistance iv. temperature of wire a) electrical resistance increases as temperature increases 6. path of least charge i. electric charge will flow thru the path with lower resistance.

Quiz 2.2 1.the potential difference between 2 places; voltage 2.the battery is the voltage source, wire is conductor. 3. toy can lengthen the wore or make it thinner 4. electric current - continuous flow of electric charges through material. 5. insulator-material through which charge cannot easily flow. 6. voltage - another name for potential difference. 7. resistance- the measure of how difficult it is for charges to flow through a material 8. voltage source- device that creates a potential difference in an electric circuit. 9. conductor - material through which charge easily can flow. 10. electric circuit- complete, unbroken path through which electric charges can flow

Study Guide 4. places of higher electrical potential energy to places of lower potential energy. 9. voltage 10.amp 12. true 29. a conductor is a material thru which charges can easily flow. In a conductor, an atom contains electrons that are loosely bound and are able to move throughout the conductor. An insulator is a material thru which charges can't flow easily. The electrons in an insulator are bound tightly to their atoms ad do not flow easily.