INDUCTORS   This is a very wide and mesmerizing field to study. examples-motors,generators,speakers   This item is based on the theory of the creating elector magnetic field when flowing current.                               Identify this we can use right hand rule.      If you make a coil by bending the conductor a magnet will be created. magnetic fields are going through the coil. Even though this magnetic field isn't efficient to lift a weight. To improve the power of the magnetic field you should use a core.   There are three main facts which influence to inductive.    Current flowing through the conductor  Number of threads  The core which you used (air core<ion core<fa-ride core)