Contents
Cal Poly Pomona
BroncoDirect Campus Map University Library

Physics Demonstrations at Cal Poly Pomona

Demo Index:
    EM-A-ES
Pira Index:
    5A 10.10
Title:
    ELECTROSCOPES
Description:
    Demonstrates the principles of static electricity.
Equipment:
    1. Braun electroscope
    2. Pith ball electroscope
    3. Projection electroscope
    4. Friction rods PVC pipes and acrylic
    5. Pieces: silk, chamois, and paper towel
Procedure:
    1. Rub rod using fur, silk, or wool to give it a charge. Glass rubbed with silk takes on a positive charge as the silk removes electrons from the glass. Amber becomes negatively charged as it strips electrons from fur.
    2. Hold rod close to the electroscope receiver & watch the leaves separate.

    (Charging by contact--touch rod to receiver;electroscope is charged same as rod. Charging by induction--bring rod near receiver, touch knob with your finger. Pull finger away, then rod; electroscope is charged oppositely to the rod.)