Types of circuit

There are two types of electric circuitA collection of wires and electric components connected together in such a way that electric current can flow through them. - series and parallel.

Series circuits

We've already come across series circuits. In this type of circuit, the components are arranged end to end and so the electric current flows through the first component, then through the next component and so on, until it reaches the battery again.

Here's a series circuit to remind you.

Simple series circuit

Use Circuit Builder to see what happens if you add more bulbs to a series circuit.

If there's a gap in a series circuit or maybe one of the components has broken, the current can't flow and so, the whole circuit turns off.

Parallel circuits

In parallel circuits, the components don't have to be end to end because the circuit can have branches.

Parallel circuit

In a parallel circuit, the current splits as it reaches a branch so the current flows around both branches.

If there's a gap or broken component in one of the branches of a parallel circuit, the component(s) in other branches will carry on working.

Use Circuit Builder to see what happens if you make a gap in one of the branches of a parallel circuit

More parallel circuits

If we put a switch in each of the branches of a parallel circuit, we can control each component separately.

Lighting ring main

This is how our homes are wired; each room has it's own parallel lighting circuit so, if a light bulb blows, the other light bulbs stay lit.

13Amp ring main

The 13 Amp mains sockets in our homes are also wired in parallel.

We call these parallel circuits ring mains.

The national grid is also a parallel circuit - but on a massive scale!

Did you know?

In 1800 Alessandro Volta built the world's first battery from discs of copper and zinc sandwiched between cardboard moistened with a salty water.
What is a volt? And why is it called a volt? The volt measures electromotive force. It was named after the Italian inventor Alessandro Volta (1745-1827)
Today we still use words that Benjamin Franklin (1706-1790) introduced: battery, conductor, positive and negative charge, electric shock and electrician.
Save energy - Finished playing on your games console or other equipment? Remember to switch off!
In 1831 Michael Faraday demonstrated electromagnetic force at the the Royal Institution in London, a famous centre for scientific education and research.
Benjamin Franklin (1706-1790) developed the first lightning conductor after flying a kite in a thunderstorm. A spectacular but very dangerous experiment!
All electrical appliances are rated in watts (W) or kilowatts (kW) ( One kilowatt is the same as 1,000 watts). You can use the ratings to compare how much electricity they use.
What is a watt? Why is it called a watt? It's a unit measuring electric power, named after James Watt (1736-1819).
In 15 minutes, the sun radiates as much energy onto Earth as all the people on the planet during an entire year. Just imagine if we could channel the sun's energy effectively!
At Deptford in 1891, electrical engineer Sebastian Ziani de Ferranti (1864-1930) designed and built the first power station and supply network. His basic system is still used around the world.
In August 1887 the London Electric Supply Corporation commissioned Ferranti to build the first power station. Today our electricity supply is still based on the system that Ferranti designed.
The first turbine engines were designed by Charles Parson (1854-1931). Today turbine engines used to generate electricity are still based on his designs.
Michael Faraday (1791-1867) is one of the most famous people involved in the discovery and harnessing of electromagnetic force.
Michael Faraday (1791-1867) was the first person to create a way of generating a constant current of electricity. His invention led to the power stations we know today.
An electric eel can produce powerful electric shocks: up to 500 volts and one ampere of current (in other words, 500 watts).
Save energy - Make sure the dishwasher and washing machine are full before you turn them on and use the lower temperature settings.
High voltage electricity is carried across the country by pylons and 'stepped down' for domestic use at substations. The National Grid supplies electricity all over the country.
Electricity used at home is metered in 'units' or kilowatt hours (kWh). Each unit is the same as 1,000 watts of electricity used for 1 hour. 1 unit = 1kWh.
Modern power stations and steam turbines use the same engineering principles that James Watt (1736-1819) applied when he invented the steam engine.
In 1771 Luigi Galvani used electricity to make a dead frog's leg jump!
Electric shock victims often can't let go of the thing that is passing the electric current into their body. That's because the electricity makes their muscles contract.
Save energy - Use energy efficient light bulbs and, when you are leaving a room empty, remember to turn the lights off.
Fossil fuels won't go on for ever - coal could run out in 250 years.
Save energy - Don't forget to switch your TV and computer off when you have finished using them.
Fossil fuels won't go on for ever - oil could run out in 30 years.
Save energy - Boil just enough water for the number of hot drinks you want to make - that way you won't waste energy.
In the 1780s, Alessandro Volta invented the first battery - all because of Luigi Galvani's experiments with dead frogs.
Thomas Alva Edison 1847-1931 is one of the most successful inventors ever, applying for over 1,300 patents by 1910, mainly to do with electrical or mechanical development.
The Italian inventor Alessandro Volta (1745-1827) is best known for his work on electric current.
The ampere is named after André-Marie Ampère (1775-1836). He discovered many of the mathematical principles of electromagnetism.
Fossil fuels won't go on for ever - gas could run out in 40 years.

Types of circuit

Series circuits

Parallel circuits

More parallel circuits

Danger

Did you know?