Basic Electrostatics System
Model No. ES-9080
16
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•
Always remove any stray charge on the necks and handles of the
charge producers by touching the necks and handles to the
grounded shield. You must also be grounded while doing this. It
also helps if you breathe on the neck of the charge producer, so
that the moisture in your breath removes any residual charge on
the neck.
• Rub the white and blue surfaces together to separate charges.
• Keep in your hand only the producer you are going to use. Put
the other charge producer away, far from contact with any of the
ice pail surfaces.
• Before inserting the charged disk in the ice pail, make sure
you’re touching the grounded shield.
4.
Carefully insert the charged object into the ice pail, all the way to
the lower half of the pail, but without letting it touch the pail. Note
the electrometer reading.
5.
Remove the object and again note the electrometer reading. If the
handle never touched the pail, the reading must be zero.
Question: Why was there a potential difference between the pail
and the shield only while the charged object was inside?
6.
Push the
Zero
button to remove any residual charge. Now insert the
object again, but let it touch the ice pail. Make sure your students
know and see that you are touching the ice pail with the charged
disk this time.
7.
Remove the object and note the electrometer reading.
Questions: Why is there now a permanent potential difference
between the ice pail and the shield? Where did the charge on the ice
pail come from?
8.
To show that the charge gained by the ice pail was lost by the disk,
ground the ice pail to remove all charge. Press the ZERO button to
remove residual charges from the electrometer. Insert the wand
again into the ice pail. Does any charge remain on it?
Procedure 1B: Conservation of Charge
1.
Starting with initially uncharged charge producers, rub the blue and
white materials together. Follow the general procedure for charging
listed in part 1A, except that in this case you must keep both producers
