Hello rustyiii,
Great questions!
"A friend claims that the has disassembled a charged Leyden Jar,
touched all of the pieces put it back together and them discharged
it."
Q. Is this possible? How?
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Yes it is. At the following example you will note that that is states
the jar can be carefully taken apart by hand, using a 'dissectible'
Leyden Jar.
Dissectible Leyden Jar
"The inner can is lifted out with an insulated tool, or, with care, by
hand. At this point the parts of the jar are safe to handle, and the
glass jar can be lifted out, the inner and outer cans touched to each
other, or touched to the glass jar in any combination. You can even
give the pieces to the students to handle...."
http://www.physics.ucla.edu/demoweb/demomanual/electricity_and_magnetism/electrostatics/dissectible_leyden_jar.html
The 'how' of the question is also answer at the link above. You will
probably get a better understanding when I explain 'why' below.
Q. Why?
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The Layden Jar is the earliest form of a capacitor. A capacitor stores
electrical charge, as does the Layden Jar. The jar material is the
dielectric, as it is the material between the two layers of metal.
When the static electricity is applied, here is what happens:
1) The charge causes a potential difference in the outer metal and
inner metal.
2) The charge is stored in the dielectic, as current will no pass
through it.
3) Once taken apart the charge still resides in the dielectric. (glass
etc..)
You can handle all pieces including the dielectric with stored
electrical energy. This is because there is no discharge path. Once
the Layden Jar is reassembled, the energy still stored in the jar can
be disharged by providing a path for electrical current to flow. In
most cases this is done by shorting the inner 'metal' to the outter
metal. Since these two conductors have a potential difference (one is
grounded), the electrical energy takes the path of least resistance,
and is discharged!
Interesting experiment isn't it? You can find more resources here for
more interesting facts :
Make your own Layden Jar
http://fargo.itp.tsoa.nyu.edu/~lewis/electricity/pages/xleyden.html
Layden Jar - defined
http://www.wikipedia.org/wiki/Leyden_jar
To assist with this answer I searched Google for :
Leyden Jar
://www.google.com/search?q=Leyden+Jar
Should you need more resources or further help, please ask for
clarification. I will do all I can to assist you further!
SgtCory |
