What is a Magnet?
A magnet is an object that can produce a magnetic force around it called a “magnetic field”. Magnets attract certain types of metals such as iron, nickel and cobalt.
Let’s learn more!
A magnetic field is not visible to the human eye, however iron filings can be used to show the pattern of a magnetic field. The magnetic field around all magnets is strongest at it‛s ends – these ends are called the Poles. One end is called the North Pole and the other is called the South Pole, just like the Earth.
If you put the poles of two magnets together they will either pull together (attract) or push apart (repel); Different poles attract (North and South), similar poles repel!
Did you know… small iron rocks on the Earth‛s surface are often natural magnets and these are called Lodestones.
The Earth as a magnet
The Earth is one big magnet – it‛s magnetic field is created by the iron that is in the core of the Earth. The Earth‛s magnetic field is strongest at the North Pole and the South Pole.
Did you know… many objects is space are magnetic including the Sun!
Did you know… the Earth‛s magnetic field deflects charged particles that come from the sun (Solar Wind) and this creates the wonderful lights called AURORA that can sometimes be seen in the sky.
An electromagnet is a magnet that is produced when an electric current is passed around a piece of iron. Unlike true magnets, electromagnets are only magnetic while the electric current is switched on!
Did you know… the first person to notice that electric currents produce magnetism was a Danish scientist called Hans Christian Oersted, in 1820.
Two experiments to try at home:
Make a compass:
Make an electromagnet:
So what is happening? When the wire is attached to the battery it creates an electric current that runs through the wire, temporarily magnetising the iron particles in the nail. When the battery is disconnected the nail no longer acts as a magnet!
Hope you have fun with these this weekend! If you have a question or something to add please drop me a note in the comments below!