A solenoid coil is a type of electromagnetic device consisting of a wire wound into a helical (cylindrical) shape. When an electric current passes through the wire, it generates a magnetic field, turning the solenoid into an electromagnet. The strength of the magnetic field produced depends on several factors, such as the amount of current, the number of turns of the wire in the coil, and the material of the core inside the solenoid.

Solenoids are often used to convert electrical energy into mechanical motion. In a simple solenoid, the magnetic field pulls a metal core (plunger) inside the coil, allowing the device to act as an actuator, such as in electric locks, valves, or relays.

Key features of a solenoid coil include:

  • Coil winding: The wire is wrapped in multiple turns to create a strong magnetic field.
  • Current flow: Direct or alternating current can be used.
  • Core: Often made of ferromagnetic material (like iron), which intensifies the magnetic field when placed inside the coil.

Solenoid coils have a wide range of applications, from electrical switches to motors and fluid control valves.