1. Static Electricity and Triboelectric Effect
* Glass Rod: When you rub a glass rod with a silk cloth, electrons (negatively charged particles) are transferred from the glass rod to the silk cloth. This leaves the glass rod with a net positive charge.
* Pith Ball: A pith ball is a lightweight, often spherical object made from a material like cork or pith (a soft, spongy plant tissue). It's usually uncharged, meaning it has an equal number of positive and negative charges.
2. Charging the Pith Ball
* Induction: When the positively charged glass rod is brought near the pith ball, it repels the positive charges within the pith ball. This causes the positive charges to move away from the glass rod, leaving an excess of negative charges on the side of the pith ball closest to the rod.
* Contact: If the glass rod is then touched to the pith ball, some of the positive charges from the rod can transfer to the pith ball, giving it a net positive charge. This happens because the attraction between the positive charges on the rod and the negative charges on the pith ball is strong enough to overcome the repulsion between the positive charges.
3. Repulsion
* Like Charges Repel: Now, both the glass rod and the pith ball have a positive charge. Since like charges repel, the pith ball will be pushed away from the glass rod.
In Summary:
The pith ball is charged by either induction (the movement of charges within the ball) or by contact (transfer of charges from the rod to the ball). The pith ball is then repelled by the glass rod due to the electrostatic repulsion between their like charges.
