How does electricity affects our life?

What is matter?

Matter is everything around us & it is made up of very small particles called: Atom

Example: Our school is made up of many buildings,

buildings are made up of many bricks together, so bricks are the smallest building unit of our school.

Atom: Is the smallest building unit of matter

What’s inside an Atom?

Inside any atom there are small, tiny particles called: electric charges

Electric charges can have: Positive charges (+)

Negative charges (-)

Properties of electrical charges?

Charges interact: {Unlike charges attract} Positive charge & negative charge attract

{Like charges repel}Positive repel positive & negative repel

negative

Examples

Rubbing a balloon with a piece of wool cloth, & then approaching it to another balloon.

{They will attract}• Rubbing two balloons with a piece of wool &

approaching them to each others. { They will repel}

Charges Add up: - When two objects touch, charges move from

one object to another.{Negative charges moves faster than

positive charges}A built up of charges:

- When something have more one kind of charges than the other

Examples

When a balloon is rubbed with a piece of wool cloth, negative charges move from the wool to the balloon, the balloon will have a built up of negative charge & the wool will have a built up of positive charge.

Static electricity

The build up of electrical charges on a body is called: “Static electricity”

Charges move:

It is the fast movement of charges

{When you move on a carpet, negative charges rub off the carpet onto you, your body gets a built up of negative charges , the charges keep building until you touch something, then they discharge to whatever you touch & that’s why we feel a

small shock}

Discharge

It is the discharge of static electricity during a storm

{ Inside a storm cloud, ice & water droplets rub against one another, some pick up positive charges & move to the top of the clouds; while others pick up negative charges & move to

the bottom, when the build up gets large enough, the charges jump to the ground as lightening}

Lightening

Electric current

It is the flow of electric charges

{ To make an electric current, you need a path that carry it, the path through which the electric current flow is called: A circuit}

The electric circuit

- A circuit should consist of:

Power source

Load Connector

Battery Lamp Wires

Light bulb Switch

Battery

Wires

N.B:- Some circuits have switches that turn the

current electricity on & off.- The flow of electric charges through a circuit

is called: Current electricity

Closed circuit

It is a circuit which doesn’t have any gaps; a complete, unbroken circuit.

Open circuit

A circuit with gaps is called: Open circuit & current will not flow through it.

Types of circuits

Series circuit

In a series circuit, the electric current flows in the same direction along a single path.

The same current goes through all the loads.

Series circuit

Parallel circuit

In a parallel circuit, the electric current flows through more than one path; these different paths are called: Branches.-The branches of a parallel circuit divide the electric current among them.

Parallel circuit

How to use electricity safely?

There are certain materials that can affect the flow of the electric current.

Some times the current flow is so high, this can cause dangerous things like: fires

That’s why we use things to slow down the flow of electric currents.

Resistance

- It is the ability to slow down or oppose an electric current

{When a current flow with a small resistance, a short circuit can result; short circuits can be dangerous as the wire heats up & cause a fire}

 

1 -Fuse

- It is a devise that helps to prevent short circuits.{It has a thin strip of metal in it, the strip has high

resistance, if too much current flow through, it melts, the circuit opens & the current stops

flowing}

- It is used once only.{As the metal strip melts so it cannot be used again}

- It is a switch that protects circuits.{ When the current is dangerously high, the switch

open & the current doesn't flow}

- It can be reset “used more than once”

2 -Circuit breakers