Question

In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as nichrome is used, not pure metals

Answer 1

Alloys unlike pure metals meet the requirements of high metal point and resistivity.

When you create alloys from metals you form certain bonds between the metal and the other substance you mix to make the alloy.

These newly formed bonds bind the alloy which have been turned from pure metal due to doping.

These bonds don’t let it melt free at relatively higher temperatures than parent metal.

We therefore use alloys since they have high melting point and high resistivity.

Answer 2

i) The Appliances like iron, electric toaster, etc. works on the principle of heating effect of an electric current.

ii) At high temperature pure metal can get oxidised and also pure metals have low resistivity.

iii) An alloy such as nichrome, has high Resistivity and can be heated to a high temperature without undergoing oxidation.

iv) Thus, Nichrome is preferred over other pure metals and I used for making coil for devices working on heating effect of electric current.