Kelvin Water Dropper

 

Kelvin Water Dropper demo picture

  • Principle: Charge separation by induction.
  • Fill container with water. As water drips through copper
    rings, metal canisters become polarized (to see why, check out this link:
    Kelvin’s Thunderstorm).
    Bend copper arms so that the thin conducting wires (attached to each arm)
    are close together but not touching. After 10 or 20 seconds of drip time touch
    the two conducting wires together using a non-conducting rod (pencil), little
    light bulb should blink at the moment of contact.
  • Tricks to making it work: Make sure base is dry (to keep
    canisters electrically isolated); position copper rings at a location that
    is just below where the water stream breaks apart into droplets; hold a charged object (i.e. charged nylon rod) close to one of the copper rings as the water is dripping to get the charge separtation process started.
  • Located in L01; section A2; covered in plastic bag.