General Physics 2Current & Resistance1 Electric Currents (R)
Chapter 19: Electric Charges and Currents 19-4 and 19-5: Electric Circuits and Electric Power.
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Transcript of Chapter 19: Electric Charges and Currents 19-4 and 19-5: Electric Circuits and Electric Power.
Chapter 19: Chapter 19: Electric Charges and CurrentsElectric Charges and Currents
19-4 and 19-5: 19-4 and 19-5: Electric Circuits and Electric Electric Circuits and Electric
PowerPower
Electric CircuitsElectric Circuits
• An electric circuit provides a complete, closed path for an electric current.
• An electric circuit consists of a source of energy (voltage source), a load (resistance), wires, and a switch
Electric CircuitsElectric Circuits
• SourceSource:: battery, thermocouple, etc.
• LoadLoad:: uses electric energy (light bulb, appliance, etc.) - offers some resistance to current flow
• SwitchSwitch:: opens and closes the circuit
• A current needs a closed path - if a switch A current needs a closed path - if a switch is off, the circuit is open.is off, the circuit is open.
Parts of an Electric CircuitParts of an Electric Circuit
Load (Light Bulb)
Source (Battery)
Electric CircuitsElectric Circuits
• Electricity cannot flow through an open circuit. Electricity can only flow through a closed circuit.
Closed CircuitClosed Circuit Open CircuitOpen Circuit
Series and Parallel CircuitsSeries and Parallel Circuits
• SeriesSeries CircuitCircuit:: circuit in which all parts are connected one after another. If there is a break, the entire circuit is opened and no current flows
• ParallelParallel CircuitCircuit:: circuit in which different parts are on separate branches. If there is a break, electrons can still move.
Series and Parallel CircuitsSeries and Parallel Circuits
Series CircuitSeries Circuit
Parallel CircuitParallel Circuit
Series and Parallel CircuitsSeries and Parallel Circuits• FuseFuse:: this strip of metal
used for safety because when the current flowing through it becomes too high, it melts and breaks the flow of electricity
- Protects against too much current flow (overload)
- Once fuses burn out they must be replaced
Series and Parallel CircuitsSeries and Parallel Circuits
• Circuit Breaker: reusable device that protects a circuit from being overloaded
- Easier to use than fuses
Electric PowerElectric Power
• Electric Power is the ratio at which electric energy is used by doing work, or by changing to a different form, such as heat or light
Power = Voltage x Current
P = V x P = V x II
Watts = Volts x Amperes
Electric EnergyElectric Energy
Energy = Power x Time
E = P x tE = P x t
Kilowatt-hours = Kilowatts x hours