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Electrical Systems - Coggle Diagram

- - - - Positive charges (protons)
      - Negative charges (neutrons)
      - Measured in coulombs
  - - - electrical components that convert electrical energy to other forms of energy
    - - To provide a path through which electrical energy to other forms of energy
    - - power source to supply energy
    - - opens and closes a circuit safely and conveniently
  - - - Ampere (A)
      - I=Q/t
    - - Ammeter
      - Must be connected in series
  - - - Voltmeter parallel to load in a closed circuit
  - - - R=V/I
    - - Has resistance of fixed value
    - - Has resistance that can be varied
    - - increases when...
        
        length of wire increases
        
        material with higher resistivity is used
        
        cross-sectional area, radius or diameter decreases
      - Ohm's Law
        
        Ohm's law states that the current through a metallic conductor is directly proportional to the voltage across it, provided that physical conditions remain constant.
  - - - Electrical components are connected in a single continuous path
      - The bulbs can last longer
      - When one bulb is removed or broken, the circuit is broken
      - The 2 bulbs are less bright
    - - The electric circuit is split into more than one path
      - If one bulb is removed or spoilt the other bulbs will continue to light up
      - Current will flow through the separate branches
      - The 2 light bulbs are brighter
      - The bulbs use up energy from battery faster
- - - - heating elements are usually made of nichrome
      - application
        
        light bulb
        
        tungsen filament
        
        electric kettle
        
        nichrome
    - - used to make electromagnets
        
        temporary magnet
        
        can be turned on and off
      - how to strengthen
        
        increase size of the current
        
        increase number of coils around the magnet
        
        use a soft iron core
      - application
        
        industrial use (electromagnet)
        
        electric bell
    - - cause chemical reactions in substances
      - application
        
        electrolysis (decomposition into constituent elements)
        
        electrolysis (extraction of reactive metals)
        
        electroplanting
  - - - P=E/t
    - - kilowatt (kW) = 1000 W
      - megawatt (MW) = 1000000 W
  - - - Can be a hazard to humans or property
        
        Electric Shocks
        
        Explosions
        
        Injury or death
        
        Electrical fires or burns
      - Causes
        
        Damaged Insulation
        
        May cause a short circuit
        
        Where a large a current flow results in overheating of wires
        
        Overloading and overheating of cables
        
        When many appliances are connected to an adapter, the current flowing in the mains circuit increases, leading to overloading and overheating, causing a fire
        
        Damp Condition
        
        Dry human skin has very high resistance but wet or broken skin may cause it to reduce.
  - - - 1kWh=1000W x 3600s=3600000J
  - - - A safety device made of a thin fuse wire inside a protective casing
      - Connected to the live wire
      - Fuse wire melts when current flowing through it exceeds fuse rating
    - - Earth Wire
        
        Green and yellow stripe
        
        Connected to ground
        
        does not carry any current under normal operation
        
        Connected to the metal casing of an appliance
        
        When a fault occurs and live wire touches the metal casing
        
        The metal casing becomes live at 230V
        
        If earth wire is connected to metal casing, current flows through earth wire instead of user
        
        Earth wire has very low resistance
        
        Large current through the earth wire melts the fuse and opens the circuit
      - Neutral wire
        
        Blue
        
        Low potential wire
      - Live wire
        
        Brown
        
        High potential wire
      - Fuse
        
        limit current flowing through appliance