the heating element is usually made of nichrome wire coiled round an insulating fire-proof material,e.g. fire-clay,sillca or mica. nichrome is chosen because of its high resistivity and high malting point. it does not oxidise easily even at high temperatures. when the electric current flows through the wire,it heats up. the rate at which the electrical energy is converted to thermal energy depends on the size of the current and the resistance of the element.
the thermal energy produced