Code Number: 5A10.36

Demo Title: Equality of Charge - Charge Conservation

Condition: Good

Principle: Electrostatics

Area of Study: Electricity & Magnetism

Equipment:  

Electrometer, Electrometer Cage, Metal Can, Insulating Block, Tall Candle, Distilled Water

Procedure:  

Place the can on top of the insulating block.  Place the candle in the can and fill with distilled water until the candle just starts to float but is still sitting on the bottom of the can.  Too much water and the candle will float and turn sideways.  Use a grounding wire to ground the system before you do the demonstration.  Set the electrometer on the 3 volt scale and zero.  Pull the candle quickly out or the water and insert into the wire cage without touching the cage.  A voltage should be registered and then the meter should go back to zero when the candle is removed.  The faster you pull the candle out of the water, the greater the charge separation.  The candle may pick up a charge that must be removed before the demo.  The best way to do this is to not rub the candle, but to just hold it in your hands for several seconds.  NOTE: This is a demonstration that is extremely touchy.  Much practice will be needed to do this correctly with good results.  

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