ELECTRICITY

Sources of electricity

1.     Electricity is a form of energy.

2.     Many appliances in our home need electricity to work such as light, television, radios, irons, refrigerator and rice cookers.

3.     The electricity that we use everyday comes from different sources.

4.     There are various sources of electricity.

DRY CELL

1.     Small and light.

2.     Supplies slight electrical energy.

3.     Contains chemicals that react so that chemical energy is changed to electrical energy.

4.     Does not last long and is thrown away when the chemical substance inside is used up.

5.     Normally used for torches, toys, stereos, remote controls, alarm clocks, etc.

SOLAR CELL

1.     Absorbs solar energy and transforms it into electrical energy.

2.     Solar cells are used in some calculators and watches.

3.     Some water heaters also use solar energy.

ACCUMULATOR

1.     Consists of a few lead plates immersed in dilute sulphuric acid.

2.     Lead plates react with dilute sulphuric acid to produce electrical energy.

3.     Heavy.

4.     Supplies greater electrical energy compared to dry cell.

5.     Lasts longer and can be recharged.

6.     Normally used in motor vehicles.

DYNAMO

1.     Normally fixed  to bicycle wheel.

2.     Produces electrical energy from magnetic rotation.

3.     Normally used to light up bicycle lights.

HYDROELECTRICAL POWER

1.     Produces great electrical energy.

2.     It is like a big dynamo.

3.     The dynamo rotates using energy from fuels or a waterfall.

ELECTRIC  CIRCUIT

1.     An electrical current only flow through a complete circuit.

2.     A simple complete circuit is build by connecting a dry cell, wires and a bulb correctly.

3.     we can also build different electric circuits using dry cells, wires and a bulb.

4.     A bulb will not light up if the circuit is incomplete.

5.     There is no complete path along which electric current can flow from one terminal of dry cell through the wires and back to another terminal.

COMPONENTS IN AN ELECTRIC CIRCUIT

1.     The main components in an electric circuit are as follows:

a.      dry cell (battery)

b.     Bulb.

c.     Connecting wires.

d.     Switch..

2.     The function and symbol of each component in an electric circuit are shown in table below.

Components	Function	Symbol
Dry cell	Supplies electrical energy
Bulb	Produces light
Connecting wires	·        Connect components in electric circuit. ·        Conduct electrical energy.
Switch	Connect and breaks electrical circuit

DRAWING CIRCUIT DIAGRAMS

1.     We can draw the circuit diagram by using symbol for each component in an electric circuits.

2.     These diagrams tell us how the components are connected in a circuits.

3.     The ways to draw different electric circuits are shown in table below.

Electric circuit	Diagram