1. The working of heating devices such as toaster and an electric iron is based on the heating effect of electric current. i.e. conversion of electric energy into heat by passage of electric current through a metallic conductor
2. An alloy, such as Nichrome, has high resistivity and it can be heated to a high temperature without oxidation, in contrast to pure metals. Therefore, the coils in heating devices such as toaster and an electric iron are made of an alloy, such as Nichrome, rather than a pure metal.