ELECTRIC CIRCUITS Introduction to electricity We use electricity

ELECTRIC CIRCUITS

Introduction to electricity � We use electricity to run our gadgets and devices, you even use electricity in school just look at the tube light or the computer your viewing this. � Many of you think how electricity that is used to run appliances at home is different than you use it in torches or a remote.

Old fashioned Greek � As every thing you see is taken from Greek language electricity is also taken from Greek word � Electricity comes from a Greek word said electkron or amber

Nature of electricity � If one need to understand the nature of electricity he or she should know that all matter is made up of a small constituent of matter called atom

Electric circuit When the positively and negatively electrons in the cell the balance of this gets disturbed and starts to move around the material this movement of electrons is called electric circuits Electric movement

Electric cell Have ever looked what powers the remote , torch and the alarm clock at home? � Yes , it is the batteries that power them up. � They are of different sizes and types and produce electricity from the chemical it contains. � After the chemical get used up they are of no use. � They are also called dry cells , with a positive �

� And negative side marked + and – on the battery � There is a metal protruding[means not flat] capping in the positive charge to indicate that is side is a positive side and on the negative side there is a flat disc shaped metal. Positive and negative sides

Crack out the cell � What happens when we open the cell? � We find chemical powders through which the electric current pass through. � When the chemical dry up they will become of no use and has to be replaced by new ones. Inside the battery

Types of batteries � Non-rechargeable: this means this type of battery can not be recharged, most of the people don’t refer to this type of battery � Rechargeable : this type of battery can be recharged using a battery recharger, most of the people refer to this type of battery Rechargeable battery

it is dark!! Help me � What do you if it gets dark ? � We use a electric bulb � Thomas Edison has invented the electric bulb which we use days for lighting

Electric bulb � The electric bulb has a outer glass casing which is fixed to a metal base a coiled wire of copper is seen inside the bulb which is called the filament which is then connected some thicker wires. � The thick wires is connected to the metal base which has negative and positive sides. Filament Metal base

� Inside the casing there is gas that does not react to its surrounding's which would keep the filament cool but not hot In the few decades scientist say, that cfl (compact fluorescent lamps) was of good use but now research shows led (light emitting diodes ) are better than cfl

Electric current/circuit � Electricity can pass through if the circuit is complete and closed path of conductors. Such a complete path, through which current can flow is called electric circuit � A simplest circuit contains of mainly of four element. � 1: a source of electricity -cell /battery � 2: a path of flow – connecting wires

� 3: a switch that can turn on/off- switch. � 4: a device for the flow of electricity-bulb

Electrical switch � Electrical switch is a simple device that can break or complete a electric circuit

Electric symbols � The components of a electric circuits such as bulb, wire , battery etc. can be shown with the help of symbols , let us see some of them-

battery

wire

switch

bulb

Conductors � The objects which allow electricity to pass freely are called conductors. � example: steel, wires, copper, iorn

insulators � The objects that do not allow electricity to pass through them are called insulators. � Example: wood, plastic, cloth etc.

Types of current � Dc (direct current)this type of current is found in cells and batteries. These are not dangerous types of current and maintain a flow of electricity. � Ac (alternating current) this type of current is found in electrical outlets and is very dangerous they do not maintain a flow of electricity.

Worksheet 1 � Write the symbol name battery Alternating current switch wire Direct current bulb

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