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9Sci CH21
9th Science CH21 Electricity
Term | Definition |
---|---|
circuit | a closed path through which electrons (electricity) flow |
conductor | a material that allows electrons to move easily through it |
current | the flow of electrons through a wire or any conductor; measured in amperes (A) with an ammeter |
dry cell | a power source that acts as an electron pump and generates electrical current by a chemical reaction; “dry” because it uses a thick, pasty electrolyte |
electric field | any area surrounding an electron that exerts a force on anything nearby with an electric charge; is strongest nearest the electron and weakens with distance |
electrical power | the rate at which electrical energy is converted to another form of energy; electrical power is expressed in watts (W) or kilowatts (kW) |
electroscope | a device containing two suspended metal leaves in a jar that move apart when charged; used to detect the presence of electrical charges |
insulator | a material that does not allow heat or electrons to move through it easily |
kilowatt-hour | the unit of electrical energy; 1 kilowatt-hour (kWh)=1000 watts (W) of power used for one hour |
Ohm’s law | states that potential difference=current x resistance, or V (volts) = I (amperes) x R (ohms) |
parallel circuit | an electrical circuit where the current flows through more than one path; if one path is interrupted, current will still flow through the other paths |
potential difference | the difference in electric potential energy between two different points; measured in volts (V) |
resistance | the opposition to the flow of electrons through a conductor; measured in ohms |
series circuit | an electrical circuit where the current has only one path; if one path is interrupted in any point, it stops current flow in the entire circuit |
static electricity | the net buildup of electric charges of an object |
wet cell | a power source that generates electric current by a chemical reaction; “wet” because it uses a liquid electrolyte |