1. Static Electricity

Static electricity is the accumulation of electric charges on the surface of an object when the charges are at rest and do not flow as an electric current. It occurs due to the transfer of electrons from one object to another.

The word “static” means stationary or not moving.

Examples include:

• Hair standing up after rubbing with a balloon

• Clothes sticking together

• Small electric shocks when touching metal objects

2. Electric Charges

There are two types of electric charges:

Positive Charge

An object becomes positively charged when it loses electrons.

Negative Charge

An object becomes negatively charged when it gains electrons.

Only electrons move during charging; protons remain fixed in the nucleus.

3. Methods of Producing Static Electricity

Charging by Friction

When two different materials are rubbed together, electrons are transferred from one object to the other. One becomes positively charged and the other becomes negatively charged.

Examples:

• Glass rod rubbed with silk

• Plastic rod rubbed with wool

Charging by Conduction

When a charged object touches a neutral object, electrons move between them and the neutral object becomes charged.

Charging by Induction

A charged object is brought near a neutral object without touching it. Charges inside the neutral object rearrange due to attraction and repulsion, causing one side to become charged.

4. Properties of Static Electricity

• Charges remain at rest

• Exists on the surface of objects

• Can cause sparks and shocks

• More noticeable in dry conditions

• Remains until discharged

5. Discharge of Static Electricity

Discharge occurs when excess charge flows away, usually to the ground. This can happen suddenly as a spark or slowly through air.

Lightning is a large-scale discharge of static electricity in nature.

ATTRACTION AND REPULSION

6. Law of Electric Charges

Like charges repel each other. Unlike charges attract each other.

7. Attraction

Attraction occurs when objects with opposite charges are brought close together. The positive and negative charges pull toward each other due to electrostatic force.

Examples:

• A charged balloon sticking to a wall

• A plastic comb attracting small pieces of paper

8. Repulsion

Repulsion occurs when objects with the same type of charge are brought close together. They push away from each other.

Examples:

• Two negatively charged balloons moving apart

• Two positively charged rods repelling