What are main components of electromechanical relay?

Answer 1

1.The coil which consists of copper wire wound around an iron core.When a current is passed thru the copper wire windings it produces magnetism,which causes the next coponent-the armature- to be attracted which then operates,ie is pulled to the coil/iron core,that then levers the springsets on which are the electrical contacts.A relay is really a device which switches on or off another circuit/s,it could be called a remotely operated switch.

Answer 2

Soft iron core,coil or winding,armature,spring,pairs of electrical contact