ELECTRICITY

Made up of parts that work together to perform a function

Electrical Components

Inputs and Outputs

Input; e.g switch

Output; e.g lightbulb

Simple electrical systems will consist of

connecting wires

lightbulb

switch

electric cells

Resistance

occurs when electrical components act as an obstacle against the flow of electrons

Measured with Reseistors

SI unit: Ohm (Ω)

Current

The flow of electrons in one direction in a circuit

Measured with Ammeter

SI unit: Ampere (A)

Potential Difference

Amount of potential energy that is changed into other forms of energy when an electron passes between two points

Measured with Voltmeter

SI unit: Volt (V)

Represented by Circuit Symbols

Heating effect

Electrical Energy -> Heat Energy

Applications of heating effect

Kettles, Toasters, Irons, etc

has a heating 'element' inside of appliance which becomes very hot when current flows through

Magnetic effect

Electrical Energy -> Magnetic Force

Applications of magnetic effect

Magnetic Cranes

able to separate iron&steel objects and non-magnetic materials using its powerful electromagnets

Electric Bells

the electromagnet inside the bell switches on and off very quickly, causing a hammer to vibrate, thus hitting the metal gong which produces the sound of the bell

Electric Motors

a machine that converts electrical energy into kinetic energy

Vacuum cleaners, electric trains, fans, etc

Chemical effect

Produces new compounds/ causes compounds to break down

Electroplating

A metallic object is covered with a thin layer of another metal

Electrolysis

The decomposition of a compound by an electric current

Reactive metals, such as sodium and aluminum, can be obtained. A solid compound of the metal is heated until it melts. An electric will then be passed through the molten compound which will break down to give the reactive metals.

2 main sources

Mains electricity

Mains electricity is generated in power stations and supplies a lot of electrical energy. It can give us a electric shock that can kill us. It is delivered to homes and factories through wires and finally to a connection point in the wall called the mains socket.

Electric cells

Electric cells supplies only a small amount of energy. They are safe to touch and used in many portable devices

Overloading

This can cause a fire in the house wiring or the adaptor

Wet Conditions

If a damaged wire or appliance was touched with wet hands, an electric current may flow through the body and get an electric shock

Short Circuits

May cause a fire in the wires or appliance

Frayed and damaged wired

If someone touches a bare wire, current will flow through the body, resulting in an electric shock

Electrical Power

the rate at which electrical energy is converted into other forms of energy

SI unit: Watt (W)

Electrical Energy

Household unit: Kilowatt-hour (kWh)

SI unit: Joule (J)