Magnetic Fields

A magnetic field is an area around a magnet where magnetic materials and also wires carrying currents experience a force.
The field around a magnet can be represented by spots around the magnet where it’s hard to see, but can be detected by placing a small compass and observing its deflection or observing the magnet’s effect on iron filings.
Magnetic fields have both direction and strength. The direction can be represented by using arrows.
The lines of a magnetic field converge at the poles where the field is strongest and spread out where it is weakest.
Magnetic fields generated by current-carrying wires are circular in shape. Increasing the current or adding an iron core can strengthen these fields.
Magnetic field lines travel from the North pole to the South pole outside the magnet, and from South to North inside the magnet. This is known as the direction of the magnetic field.
The Earth has its own magnetic field, which is why compass needles align North-South.
Solenoids – coils of wire – produce strong, uniform magnetic fields inside the coil when an electric current is applied. This kind of setup is called an electromagnet.
The principles of electromagnetism are used in many technologies, including electric motors and modern communication devices.