Q) In the centre of the earth there is a mixture of metals and produce heat upto several times. It also emits some special kinds of energy. Which type of energy is this. If it is magnetic then how it is possible?
Energy is energy my friend. There are no special kinds. The center of the Earth is molten iron. The rotating Earth causes the molten iron to move. That's about it then.
The common belief of how the Earth (like all celestial bodies) generates a magnetic field is described by something call the Dynamo Theory - this theory does not discount the effect of the movement of the conductive molten internals of the Earth on magnetic field that the Earth exhibits. That said, from my minor understanding of Dynamo Theory, it is blighted by being too complex to justify as a complete description of how the Earth generates its magnetic field, given there are a multitude of complex inter-related variables such as the Suns magnetic field and the complex construction of the Earth's mass.