Solenoid

A solenoid is a coil containing many turns of wire. Each turn produces its own magnetic field. Inside the coil, these fields point in the same direction and add together, so shaping the wire into a solenoid produces a stronger magnetic effect than a single straight section of wire carrying the same current.

A solenoid consists of many such loops, or turns, arranged closely together in a long coil. It is an example of an electromagnet because its magnetic field is produced by a current.

A solenoid goes further: it arranges one continuous insulated wire as many nearby turns wound in the same sense.

If the wire is wound into a coil, called a solenoid, every turn of wire produces its own field. Inside the solenoid, these fields point in the same general direction and add together. The resulting field is stronger and resembles the field of a bar magnet, with a north pole at one end and a south pole at the other.