Physics – 4.2.1 Electric charge | e-Consult

Production of Electrostatic Charges by Friction:

One simple experiment involves rubbing a polystyrene ball with a cloth (e.g., wool).

1. Materials: Polystyrene ball, wool cloth, a small lightweight object (e.g., a cork or a piece of paper).
2. Procedure: Rub the polystyrene ball vigorously with the wool cloth for about 30 seconds.

3. Observation: After rubbing, bring the ball near the lightweight object without touching it. The object will be attracted to the ball.

   Explanation: Friction causes electrons to be transferred from the cloth to the polystyrene ball, resulting in a net negative charge on the ball. This negative charge then attracts the positively charged atoms in the cork or paper.

Detection of Electrostatic Charges:

Another experiment to detect electrostatic charges involves using a charged object and a negatively charged plate.

1. Materials: A charged polystyrene ball (produced as described above), a negatively charged metal plate (can be made by rubbing a piece of metal with a cloth), a lightweight object (e.g., a cork or a piece of paper).
2. Procedure: Bring the charged polystyrene ball near the negatively charged metal plate.

3. Observation: The lightweight object will be attracted towards the negatively charged plate.

   Explanation: The negatively charged plate creates an electric field. The charged polystyrene ball interacts with this electric field, causing the lightweight object to be attracted towards the plate. This demonstrates the presence of electrostatic charges.