KEEP THIS PAPER AT YOUR LAB STATION
Field Mapping Lab
Purpose: To map the electric field around a charge configuration.
Equipment: Silver “charges” painted on carbonized paper, field map kit, DC power supply, digital
multi-meters.
Product: A map of the electric field surrounding a charge configuration. This should be neat,
accurate, and complete. This is your ONLY product for this lab.
Instructions for wiring your electrodes:
a) Place the carbonized paper on the cork board. Write your group member names on the
paper in the margins. Use a pencil or a light colored pencil.
b) Connect one end of the thin red electrical lead to one of the silver “charges” painted on
your carbonized paper by driving a silver thumbtack through the ring on the lead and into
the silver electrode. Press the tack all the way in! You must make good contact between
the ring and the silver paint. This will be your positive charge. Clearly mark a big “plus”
sign next to it with a pencil.
c) Repeat step b) on the other silver “charge” using the thin black lead. This will be your
negative charge. Clearly mark a big “minus” sign next to it with a pencil.
d) Connect the thin red lead to a thicker red lead using an alligator clip. Plug this into the
red (positive) DC Volt outlet on your lab table.
e) Repeat step d) for the black lead. Plug into the black (negative) DC Volt outlet.
f) Set your voltage to 6-8 Volts.
g) Call your teacher over to have him or her check your wiring.
Instructions for mapping your field:
a) Digital Multi-Meter (DMM) instructions:
 Auto-ranging (dark gray) meters: Turn on your DMM using the on-off switch
on the side and set the dial to DCV (DC Volts).
 Non-auto-ranging (black) meters: Select an appropriate voltage range with the
dial. A good choice is probably 200 m (200 millivolts).
b) Hold both DMM leads in one hand like two pencils or chopsticks. Place your black lead
on the negative electrode, near the edge. Then, without changing the spacing between the
black and red leads, swivel the red lead around the black until you have the greatest
voltage reading on the DMM. Mark the positions of the two leads lightly with a pencil.
BE CAREFUL NOT TO PUNCH HOLES IN THE PAPER WHILE YOU DO THIS.
c) Place the black lead on the mark you made for the red lead, and repeat step c). Do this
over and over until you reach the positive electrode.
d) You will have created a set of dots that start at the negative electrode and travel to the
positive electrode. This is one field line. Carefully connect the dots with a smooth curve.
Feel free to use color!
e) Put an arrowhead on the curve where it meets the negative electrode.
Make as many field lines as you can as a group in the time allowed. You must take turns drawing
the field lines. Work carefully and neatly. You will turn your drawing in as a lab report. There is
no other report requirement for this part of the lab.