is it necessary for a coil to have a magnetic core if it is to function as an electromagent? explain
It is not strictly necessary for an electromagnet to have a core made of magnetic material. However, it certainly helps. If there is no magnetic core, the magnetic flux is less concentrated. The magnetic core only concentrates the flux, thereby making the electromagnet more effective at applying a magnetic force at a point location.
As long as the material is Ferrous (Contains Iron) it can be the core of an electromagnet. There are other core materials, some are paramagnetic, and others contain little or no iron at all, but that's a discussion for another time.
