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arceo wrote:
>hii have some basic question about conductors.i) when a conductor >is at
>potential zero, can the conductor has charge on it?ii)
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Yes. Consider a conductor above ground but held at ground potential while in
the field produced by other charged conductors. It is relatively easy to
determine the charge on the conductor given the geometry and the potentials
of all the conductors. Note that the charge on any such conductor is
generally not uniformly distributed around the periphery.
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> is a grounded
>conductor same as potential zero conductor?  what is the difference?
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If the ground is taken as potential zero (reference) then a grounded
conductor can be considered as being at potential zero. Potential 0 is just
a reference - as potential is always measured between two points. Ground is
convenient for the reference but one could take a wire as reference and say
that ground is at some potential (say -500V) with respect to this wire.
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>iii) how
>do you actually bring a conducting surface to a specific potential?
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connect it to a source- generator, battery, charged capacitor.Also,  If you
have a conductor in a field, its potential depends on the field so by
modifying the field you can adjust its potential. (i.e. an insulated fence
wire, 1m above ground, under an HV line at 100KV. The integral of the field
between ground and the fence will give its potential and the field is
determined by the HV line- change its voltage and the fence potential will
change.
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iiii) >is
>this really a possible set up? a cube box of conductor which has one >face
at
>potential  V1 and another at V2 and all the other faces at V=0.
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No. If this were so there would be some mighty high currents flowing from
one face to the other- Unless the conductor was very poor, it would be
extremely difficult to do this without  very large sources (in terms of
maintaining voltage under load)-

>  isn't a
conductor supposed to be at same potential everywhere?
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If there is no current flowing - yes- with current flowing, there can be a
potential drop form one point to another- however, from the trend of your
questions - you are considering an electrostatic (or quasi-electrostatic
case) for which Yes is the answer. The surface charge will be distributed to
achieve this.

Don Kelly
dkelly@nanaimo.ark.combull
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