Physics - Electricity

• Electric Field


  The field around charged particles that exerts a non-contact force on other charged particles.
• Non-Contact Force


  A force that one object can apply to another object without touching it
• Line of Force


  The path that a positive charge would follow due to the electric field
• Cell


  Pushes electrons around a complete circuit

  
• Battery


  Two or more cells

  
• Switch


  Enable the current in a circuit to be turned on or off

  
• Lamp


  Emits light when current passes through it

  
• Diode


  A device that permits current to flow through it in only one direction.

  
• Light-emitting Diode (LED)


  combines the properties of a diode and a lamp

  
• Ammeter


  A device used to measure current in a circuit

  
• Fixed Resistor


  limits the current in a circuit

  
• Variable Resistor


  Allows current to be varied

  
• Fuse


  A safety device with a thin metal strip that will melt if too much current passes through a circuit

  
• Heater


  Designed to transfer energy from an electric current to heat the surroundings

  
• Voltmeter


  A device used to measure voltage, or electrical potential energy difference

  
• Series


  A circuit in which all parts are connected end to end to provide a single path of current.

  
• Potential Difference


  The work done by each Coulomb of charge
• Parallel


  A circuit in which parts are connected in separate circuits to each other to provide a single path of current.

  
• Charge Equation


  =Current X Time

  
  

  =I X t
• Unit of Charge

  Coulomb(s)

  
  

  C
• Unit of Current

  Ampere(s)

  
  

  A
• Unit of Potential Difference

  Volt(s)

  
  

  V
• Potential Difference Equation

  =Current X Resistance

  
  

  =I X R
• Unit of Resistance

  Ohm

  
  

  Ω
• Ohm's Law


  The current through a resistor at a constant temperature is directly proportional to the Potential difference across the resistor
• Thermistor


  A resistor that changes its resistance with a change of temperature.
• Light Dependent Resistor


  A resistor which has high resistance in the dark, and low resistance in bright light
• Total Resistance of a series circuit


  Sum of the resistances of every component
• Total potential difference of a series circuit

  Sum of the potential differences of every cell
• Current of a series circuit

  The same current passes through each component
• Potential difference in a series circuits

  Potential difference is shared between the components
• Total Current in a parallel circuit


  The sum of the currents through each branch
• Total resistance of a parallel circuit


  Always less than the resistor with the least resistance
• Alternating current


  A flow of electric charge that regularly reverses its direction.
• Live Wire


  The brown wire in a cable or plug.
• Neutral Wire


  A wire that carries current away from the component; it is coated in blue plastic.
• Step-Up Transformer


  Increases the size of an alternating potential difference
• Step-Down Transformer


  Decreases the size of an alternating potential difference
• Earth Wire


  The green and yellow wire in a cable or plug. It is there for safety.
• Three-Pin Plug


  connects an appliance to the mains