AP Physics C
Electric Fields
Electrostatic Fields
Mark H. Hoffman
Objective:
1. Using Pasco Conductive Paper, Silver Conductive Ink (in lieu of aluminum pre-cut
shapes), measure contour lines of equal voltage between two shapes, having a potential
difference between 10-20 volts DC.
2. Using the equipotential lines, draw the electric field lines normal to the equipotential
lines, to establish a mapping of the electric field between two metal conductors.
Equipment Used:
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Pasco Conductive Paper PK-9025
Pasco Silver Conductive Ink Pen PK-9031B or Pre-Cut Aluminum Electrodes
Pasco Voltmeter & Ammeter (Galvanometer) Probes
Pasco Model 750 Interface
E-Mac Computer
Conducting Wires & Alligator Clips
0-20 VDC Regulated Power Supply
Procedure:
1. Using the enclosed “Mapping of Electric Fields” Experiment, set-up and map lines of
equi-potential on the conductive paper.
2. Attach the Voltmeter and Ammeter (Galvanometer) probes to channel A & B,
respectively, of the Model 750 Interface. Be sure the interface is connected to the E-Mac
computer via the USB cable, and that the DataStudio software recognizes the connection
of the probes. Set the voltmeter scale to 0-20VDC, to monitor the potential difference
between the electrodes, and set the Galvanometer to measure ± 5 uA full scale.
3. Set the potential difference between the electrodes between 10-20V DC; set for optimum
galvanometer deflection.
4. Measure the potential difference between an arbitrary starting point (middle of the
conductive paper initially) on the conductive paper, and another point adjacent to it, to
find points which are at the same electric potential. Follow the mapping procedure in the
Experiment write-up.
5. Use the Conductive Ink Pen to draw the electrode surfaces, or the pre-cit aluminum
shapes, shown in the Board Layout, of the Experiment write-up. Do up to three electrode
geometries, time permitting.
6. Plot the equipotential lines and map the electric field lines, for each set of electrodes
used.