CIRCUITS

• open switch

  
• closed switch

  
• single celled battery

  
• variable resistor

  
• insulator


  A material that does not allow heat or electrons to move through it easily.
• conductor


  A material that allows heat and electricity to pass through it.
• conductors e.g


  aluminium, zinc, carbon, copper, paper clips
• Insulators e.g


  glass, paper, wood, plastic
• parallel circuits


  If you remove/disconnect a component, it will hardly affect the others - useful for most things e.g. cars, household electrics
• series circuit


  A circuit in which all parts are connected end to end to provide a single path of current.
• what is a voltmeter?


  a device that measures the potential difference between two points in an electric circuit
• what is resistance?


  a measure of how hard it is for electrons to flow around the circuit
• what is resistance measured in?


  Ohms (Ω)

  the larger the number of ohms the greater the resistance
• resistance=

  r=

  Potential difference divided by current

  v/a
• static electricity


  electric charge on the surface of a non-conductor.i.e. it is charge that cannot flow easily
• attract


  two unlike charged objects do this
• charge


  a property of matter, it exists in two forms ( positive and negative) which attract each other
• repel


  to push away
• positive

  negative


  gain of electrons

  loss of electrons
• electrostatic shock


  what a person gets when they are charged and then earthed
• field lines


  Lines coming from an object representing the strength of the force. The denser the lines, the stronger the force.
• positive field lines


  point outward

  
• negative field lines


  point inward