Electricity

• Parallel circuit


  If there is a break in the circuit, the other sections will still work
• Microcircuits


  Extremely small circuits, use transistors instead of conventional switches
• Transistor


  Acts as a switch within a microcircuit
• Reasons for conserving energy: so non-renewable resources don't run out, reducing environmental impact, conserving fossil fuels and reducing pollution
• Disadvantage of producing electricity using tides is it's hard to find suitable locations
• Batteries


  Large banks are expensive and bulky, need too many to power a house, need more electricity to recharge
• Fuel cells


  Generate electricity from a chemical reaction using hydrogen
• Renewable resources


  Energy that can be replenished in a short amount of time
• Non-renewable resources


  Energy that cannot be replaced as it is used up, supplies are finite
• Biomass


  Energy harnessed from biodegradable waste, produces combustible gas when decomposing
• Nuclear fission


  Splitting of atoms to release an enormous amount of energy
• Hydroelectric power


  Capture falling water to spin a turbine connected to a generator, generating electricity
• Efficiency


  The ratio or percent of useful energy that comes out of a device compared to the total energy that went in
• Wasted energy


  Energy that is not usefully transferred, e.g. friction
• Higher efficiency leads to lower energy demands
• Friction and the device's purpose limit the maximum efficiency achievable
• Conductor


  Materials that allow charges to flow freely
• Insulator


  Materials that prevent charges from flowing freely
• Load


  The item that converts the electrical energy into "work"
• Circuit


  Provides a continuous pathway for charges to move
• Primary cells


  Cannot have their reaction reversed, cannot be recharged
• Secondary cells (rechargeable cells)

  Can be recharged by inputting an electrical current
• Electrolysis


  Separates elements from solutions using electricity
• Electroplating


  Using electricity to place a layer of metal on another metal
• Electrochemical cell


  Package of chemicals designed to produce small amounts of electricity, converts chemical energy into electrical energy
• Dry cells


  Use a "dry" chemical electrolyte that is a paste or powder
• Wet cells


  Use a liquid electrolyte, usually an acid (e.g. car battery)
• Three-pronged plug


  Has an extra wire that connects the device to ground, providing another pathway for electricity
• Fuse


  Contains a thin piece of metal designed to melt if too much current passes through it
• Circuit breaker


  Has a special wire that heats up if there is too much current, triggering a spring mechanism to turn off the switch
• Grounding involves releasing charge into the earth which can easily absorb extra electrons
• Voltage


  Analogous to the height of a waterfall, determines the amount of energy
• Current


  Analogous to the width of a waterfall, determines the amount of energy
• Circuit


  A continuous pathway for electricity to flow
• Devices in a circuit

  • Plugs
  • Fuses
  • Breakers
• Three-pronged plug


  Has an extra wire that connects the device to ground
• Circuit breaker


  Has a special wire that heats up if there is too much current, triggering a spring mechanism that turns off the switch inside the breaker
• Grounding


  Releasing charge into the earth which can easily absorb extra electrons
• Components of a circuit

  • Energy source
  • Conductor
  • Switch
  • Load
• Current


  The amount of charge/electrons flowing past a single point in a conducting wire