Electrical Circuits

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Electrical Circuits
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Electrical Circuit

• Closed path through which charge can flow
• A Circuit needs
• Source of energy (voltage)
• Conductive path for charge to flow
• Source of resistance (device to do work)

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Batteries

• Provide the energy (voltage) for charge to flow
  in a circuit
• Have () and (-) terminals

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Dry cell

• Series of chemical reactions causes electrons to
  flow and accumulate at the (-) terminal
• Used in portable electronics

terminal
- terminal
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Wet Cell

• Has 2 connected metal plates submerged in an
  electrolyte solution that conducts electricity
• Ex Car battery

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Circuit Diagrams

• Use symbols to represent parts of a circuit
• Shows one or more complete paths that charge can
  flow

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Current flow
Battery

-
Current always flows from positive () to
negative (-) battery terminal
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Series Circuits

• Charge has only one path to flow
• If one device stops working they all stop
  working!
• Viewing series circuit

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Series Circuits

• Adding light bulbs to a series circuit increases
  resistance
• CURRENT DECREASES, BULBS BECOME DIMMER

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Parallel Circuits

• Circuit with two or more paths for current to
  flow
• If one device stops working the rest continue to
  work!

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Parallel Circuits

• Viewing Parallel Circuit
• Homes and buildings are wired in parallel
• Bulbs shine brighter in parallel than series
• All Directly connected to battery

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Parallel circuits

• Current in branch depends on resistance
• More current flows through the path of lowest
  resistance
• Voltage is same across each branch