What does an electric motor need in order to work?

The basic idea of an electric motor is really simple: you put electricity into it at one end and an axle (metal rod) rotates at the other end giving you the power to drive a machine of some kind. Other kinds of electric motors. Large AC motors (used in things like factory machines) work in a slightly different way: they pass alternating current through opposing pairs of magnets to create a rotating magnetic field, which "induces" (creates) a magnetic field in the motor's rotor, causing it to spin around. Basically magnets.

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab.