Direct current Electricity

Do NowWhat is Direct Current Electricity ?

List the components of a simple circuit

List few examples for insulators

List few examples for conductors

L.I: learning about Direct Current ElectricityS.C:I am able to define current electricityI am able to identify components of electric

circuit.I am able to draw simple circuit diagram.I am able to differentiate series and parallel

circuitI am able to describe the use of conductors

and insulators

Definition:The electrical current is a flow of

charged particles

Electricity is a form of energy that can be easily changed to other forms.

What is Electricity???What is Electricity???

Types of currentTwo Types of Current:DC—Direct Current—produced by solar cells and chemical cells (batteries)

Current only flows in one direction.

2nd type of current

AC—Alternating Current

Current flows back and forth (alternates)

Found in homesGenerators produce AC current

Electric ChargesElectric charges are made up of

positive charges (protons) and negative charges (electrons).

When these charges flow in a circuit, a current is produced.

How does direct electricity flow?The battery in a circuit gives energy to

the electrons and pushes them around a circuit, from the negative terminal of the cell, round the circuit and back to the positive terminal of the cell.

Electric CircuitsElectric circuits are

made up of electrical components

These components must be joined together without any gap in between to form a closed circuit.

connecting wires

electric cell

circuit boardlight bulb

Note:

Components refer to the light bulb, wires, battery

Electric CircuitsIncomplete circuits are called open circuits.

connecting wire is missing

no source of electrical energy

Both the circuits in the diagram are incomplete, hence they are known as “open circuits”.

An electric current flows only when there is: A source of electrical energy – battery, power supply A component to convert energy into another form – light, motor or

heater a complete circuit without any breaks

connecting wires

electric cell

circuit boardlight bulb

Examples of circuit diagrams:

circuit diagramsIn circuit diagrams components are represented by the following symbols;

cell battery

switch

lamp

motorammeter

voltmeter

buzzer

resistor

variable resistor

Series CircuitAll parts of the circuit are connected one

after another in a loopThere is only one path for the electrons

to followIf one part goes out

• The circuit goes from closed to open• Electricity will not flow• All parts go out

The voltage is split through each part of the circuit

The current is the same throughout the circuit

Example: Christmas Tree Lights

Series Circuit Examples

A complete circuit turns the light bulbs on

Series Circuit Examples

The burnt bulb stops the electron flow to the rest

of the circuit

This Light Bulb is Burnt Out

Parallel CircuitThere is more than one path or branch for

the electronsIf a break occurs in one branch, the

electrons can still flow in the otherThe voltage is the same throughout each

branchThe current is split through each branchExample: Household Wiring

Parallel Circuit Examples

Current divides and has more than one path

A B

PATH #1

PATH #2

Parallel Circuit Examples

Even though Bulb “B” is burnt out, the current still

goes through the other circuit and Bulb “A”

remains lit

This Light Bulb is Burnt Out B

A

Circuit DiagramsComponent Symbol Component Symbol

An electric cell Battery

Light bulb (lamp) Switch

Switch (open)

Switch (closed)

Connecting wires (not joined)

Connecting wires (joined)

+ +

Symbols are used to represent the various electrical components in circuits.

ConductorsA conductor is a material that

current can pass through easily A substance such as steel , has free

electrons and allow current to occur

InsulatorsA material in which electrons are not able

to move easily is an insulator. These does not have free electrons and

does not allow current to occurMost plastics are insulators

Examples

MetalPaper clipsSilverwareWiresWater

Tea cosy, burger box and thermos flask all prevent the transfer of heat.

Look at these things. These are insulators too.

What do they do?