Presentation on theme: "Resistance in Electrical Systems"— Presentation transcript:
1 Resistance in Electrical Systems 4.3 NotesResistance in Electrical Systems
2 Properties of Materials ConductorsInsulatorsHave a large ability to conduct electric currentThey contain many free electronsMetals are good conductorsTemperature influences resistance of the flowWhat happens to the energy when resistance is present in electrical systems?Have a lower ability to conduct electric currentElectrons are tightly boundNonmetals are good insulatorsWhat are semiconductors?
3 Variables and Units of Electricity Voltage (potential difference)- the ability to accelerate an electric charge between two points in an electric field.Measured in VOLTSCurrent- the rate of flow in a conductor.Measured in AMPERESResistance- measure of the ability of an electrical device to oppose flow of charge through a deviceMeasured in OHMS (Ω)
4 Ohm’s Law R = ρ(L/A) Measured in (Ωm) V = IR Voltage = (current) (resistance)I = V / R Current = (voltage) / (resistance)R = V / I Resistance = (voltage) / (current)Resistivity- a property of a material that describes its ability to resist flow of electric chargeResistivity is a physical property of individual materials and is influenced by temperature.R = ρ(L/A)Measured in (Ωm)
5 Types of Circuits Series Parallel A circuit with only one path for the current to flowRSERIES= R1 + R2, R3+…A circuit in which there are multiple paths for the current to flow1/RPARALLEL = 1/R1, + 1/R2 + 1/R3+ …