Electrostatic Meters: Electrostatics
Gold Leaf Electroscope
PIRA Class: 5A22.30
To demonstrate a means of relative measure of net charge.
By direct contact of charging by induction, use light weight gold leaves within the electroscope to indicate the relative amount an object is charged. Leaves will spread out more and more as they gain more and more charge, whether positively or negatively charged.
- Charging by induction: Place the object near to the electroscope, the electroscope top knob will acquire the opposite charge of the object at hand. Strips will then have the same charge as the object. (Object's net charge is not changed during this process.) The closer the object is brought to the top knob, the greater the separation of charge within electroscope, the greater the separation of the gold leaves. Move the object away from electroscope and electroscope charges will redistribute 'evenly' about, and leaves will return to original position.
- Charging by contact: Bring the object in contact with the top knob of the electroscope, charge can then transfer from object to the electroscope and its gold leaves. Leaves separate, this separation distance will depend on the amount of charge transferred. Remove object from electroscope, charged leaves will remain separated.
NOTE: If irregularities are observed in the interactions of the charged objects, it is recommended that all synthetic, including black carts, materials involved be rinsed off with water or wiped down with a wet cloth.
Charging an Electroscope by Induction Using a Negatively-Charged Balloon
Gold Leaf Electroscope, charged object