On what principle does a solenoid valve coil operate?

A solenoid valve coil operates on the principle of electromagnetism. When an electrical current is passed through the coil of the solenoid, it generates a magnetic field due to the interaction of the electric charge and the magnetic field around it. This magnetic field attracts or repels a movable core (the plunger) within the solenoid.

This action allows the solenoid valve to open or close, controlling the flow of fluid in a system. Electromagnetism combines the effects of electricity and magnetism, which is precisely what occurs in a solenoid.

In contrast, while magnetism refers to the behavior of magnets without electric current, and hydraulics and pneumatics relate to fluid and gas movement, respectively, they do not explain the specific mechanism by which solenoid valves operate. Electromagnetism is the correct and comprehensive principle underlying the function of a solenoid valve coil.