PASCO ES-9060 Charge, Equipotential and Field Mapper - Manual (Page 12)

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Model No. ES-9060 Charge, Equipotential, and Field Mapper
11
Equipotential and Field Mapping
Experiments
The following are only some suggested experiments in mapping
equipotentials and field gradients using the PASCO Field Mapper. The
true value of the equipment lies in its complete flexibility, permitting
the user to design any system of charged bodies, and then to map the
equipotentials and field gradients.
NOTE: Only power supply connections are shown in the following
schematics. Voltmeter connections are not shown because they vary
depending on whether equipotentials or field gradients are being
mapped.
Experiment 1: Parallel Plate Capacitor
Questions:
a) What is the field outside the
capacitor plates?
b) How does the ratio of the plate
length (l) versus separation (d)
affect the fringing effect at the edges
of the plates?
c) What redesign of the plates, or perhaps the extra electrodes, could
help eliminate the fringing effect?
Experiment 2: Point Source and Guard Ring
Questions:
a) What relation can be derived
between the distance from the
center of the point source and the
equipotential value?
b) Would this same relation hold if the
system were three dimensional?
c) What purpose does the large outer ring serve in this experiment?
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Schematic 1
electrodes
connecting wires
DC
source
d l
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Schematic 2