Question

what is solenoid ????

Answer 1

A cylindrical coil of wire acting as a magnet when carrying electric current is solenoid.

Answer 2

A solenoid is a coil of insulated or enameled wire wound on a rod-shaped form made of solid iron, solid steel, or powdered iron. Devices of this kind can be used as electromagnets, as inductors in electronic circuits, and as miniature wireless receiving antennas..