Electrical Engineering ⇒ Topic : Heating

Heating It is used for electrically conducting materials and uses the magnetic field set up by an alternating current. The varying magnetic field induces a voltage in the work piece which causes a current to flow in the surface.

   The phenomenon of skin effect plays an important part. It is the tendency of induced heating currents to concentrate near the surface of the conductor through which flux is set up. As we move inside the conductor eddy current becomes less and less and results in less heating.

   The current density along the cross section of bar is given as J = J₀e^-x/δwhere δ is called the depth of penetration

where x = δ,J = J₀e^-1 = J₀/e= 0.37 J₀

Heating is required for

(1) Domestic purposes

•     Cooking
•     Heating of buildings etc.

(2) Industrial purposes

•       Melting of metals
•       Heat treatment processes
•       Drying
•       Welding etc.

Practically all the heating requirements can be some form of electric heating equipment