PIRA 5A22.10 Electrostatic Meters: Electroscopes
Photo of Demonstration Used at the University of Texas at Austin.
Instructions / Notes:
- Touch the top aluminum plate on the electroscope with a finger to discharge.
- Electroscope may be used to show the effects of nearby electric field by bringing a charged PVC rod very near to the top plate - before moving the rod away.
Very near is about 3" inches from the top plate of the electroscope.
- To show conduction - place the charged PVC rod in direct contact with the top plate of the electroscope.
- To show an induced charge - place a finger on the bottom of the electroscope, as seen below.
Then bring a charged PVC rod near the top plate of the electroscope.
Before moving the charged PVC rod away from the electroscope , remove your finger from the bottom of the electrode.
- Note: This demo uses static surface charges - which require very dry air conditions for it to work effectively.
- If the air in the classroom is too humid - then the surface charges will bleed away rather quickly.
The image below shows a student charging the electroscope by induction.
The 4 minute video below is intended for staff use.
Last Updated 10/11/2018 - UT Physics Dept. All Rights Reserved.