Kelvin Water Dropper
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PIRA Classification: 5A40.70
Description: A pail of water is placed on a shelf. Water flows out of the bottom
of the pail through a small pipe which splits into two. The flow of water is controlled
by a valve. As the water leaves the spigots, the streams go through two rings and end up in
buckets below the rings. The rings themselves are connected via a conducting rod to opposite
buckets. As the water flows, charge builds up on the rings and a spark is produced between
two spheres connected to the rings. The build up is also observed with an electroscope.
Special Instructions: Charge up one ring with a PVC rod. The water streams need to
break up before they enter the rings; that is, the water should be in droplet form. If it isn't,
the effect may take longer to appear.
Ideally For: Phys 1102, 1202, 1302, 4002, 5012
Condition: Good
Setup time: 5 minutes
Safety Issues: None