Question

Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?

Answer 1

Hint:To answer the given question, first understand the meaning of alloy and pure metal and their difference. Then check for the advantages of alloys over pure metals which can improve the efficiency of electric toasters and electric irons. Use these points to answer the given question.

Complete answer:
We are asked why alloy is used to make the coils of electric toasters and electric irons instead of pure metal.First let us know what an alloy is and what pure metals are and their difference.An alloy is made up of two or more elements, of which at least one element is metal and others are metal or nonmetal.Pure metal consists of a single element.

The coils of electric toasters and electric iron are made of an alloy rather than a pure metal because of few advantages of alloy over pure metal which are;
-Resistivity of alloys are higher than that of pure metals, the reason behind this is, alloys are made up of two or more elements and the ions are randomly arranged, due to random locations of ion cores, the mean free path of electrons in alloy is greater than that of pure metal. So, the resistivity of alloys is higher than that of pure metals.
-Alloys do not melt easily at high temperatures, so alloys are preferred over pure metals.
-Alloys are harder than pure metals.
-Alloys have higher tensile strength than its constituents.
-Color of pure metal can be modified by mixing it with other metal or non metal and forming alloy.
-Alloys have more resistance to corrosion than pure metals.

Note:Alloys can either be solid solutions of metallic elements in which all the individual grains/crystals of the metals are of the same composition, or they can be mixtures of metallic phases featuring at least two different solutions, resulting in microstructures containing different types of crystals inside the alloy.