Electromagnets and transformers - AQAWhat is an electromagnet?
Electromagnetism is due to the magnetic fields around electric currents. The fields can cause forces with other nearby magnets which can be used to make motors spin.
When a current flows in a wire, it creates a circular magnetic fieldArea surrounding a magnet that can exert a force on magnetic materials. around the wire. This magnetic field can deflectTo cause something to change direction. the needle of a magnetic compass. The strength of the magnetic field is greater:
closer to the wire
if the current is increased
Solenoids
A solenoidA straight coil of wire which can carry an electric current to create a magnetic field. consists of a wire coiled up into a spiral shape. When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet. The field inside a solenoid is strong and uniform. The small magnetic fields caused by the current in each coil add together to make a stronger overall magnetic field.
Electromagnets
A solenoid with an iron core is called an electromagnetA magnet made by wrapping a coil of wire around an iron bar and passing an electric current through the coil.. The iron core increases the solenoid鈥檚 magnetic field strength. A simple electromagnet is made by coiling wire around an iron nail.
Electromagnets are used in devices such as electric bells, and door locks that can be controlled remotely.