Physics Lesson 1 (Electrostatics)

• Electrostatics: The study of electric charges at rest and their interactions.

Subatomic Particles

Charging Processes

Charging by Friction

• Occurs when two objects are rubbed against each other, causing a transfer of electrons; one object loses and the other gains electrons.

• Outcome: The object that loses electrons is positively charged, and the one that gains is negatively charged.

Charging by Conduction

• Involves direct contact between a charged object and an uncharged object, allowing electrons to flow to equalize the charge.

• Characteristics of Conductors: Materials, typically metals, that allow the flow of electrical current due to free-moving electrons.

Charging by Induction

• Charging occurs without direct contact; a charged object is brought close to a neutral conductor, causing charge separation within the conductor.

• The side of the conductor near the charged object becomes oppositely charged, while the far side acquires a charge of the same type.

• When grounded, excess electrons will flow into or out of the conductor, stabilizing the charge.

Example Activities

• Rubbing a Balloon: Rubbing a balloon with cloth shows electron transfer and resultant charges, leading to attraction/repulsion behaviors.

• Electrostatic Experiments: Students can observe charge behavior through induction by using common materials (e.g., balloons, cloth).

Law of Electric Charge

• Charges can either repel (like charges) or attract (opposite charges).

Advantages of Earthing

• Earthing: Connecting a charged object to the earth allows excess charge to dissipate safely. The earth acts as a reservoir of electrons.

• Many appliances and electrical devices require grounding to prevent electric shocks and ensure safe operation.