Question

What is Nichrome? State its one use.

Answer 1

Hint:Nichrome is an alloy that is made up of two elements- $80\% $ Nickel and $20\% $ chromium. It conducts electricity and also has high resistivity which varies linearly with temperature. Due to these properties, it produces heat.

Complete answer:
Nichrome is an alloy that is made up of two elements- $80\% $ Nickel and $20\% $ chromium. When Nichrome is heated at high temperature, it does not oxidize in air or burn easily like other metals. Also, it has a high melting point and boiling points, that’s why it does not melt or break easily when a large amount of current passes through it whereas other metals like copper and aluminium do. It can easily remain in a hot state for a long period of time without getting melted or burnt.

Now, we will draw a diagram showing the relation between resistivity and temperature as shown below

Now, specific resistance is very high at $0\,K$ temperature and it varies linearly with temperature. It has a specific resistivity which opposes the flow of current in the given substance and hence it has a high resistance. It can be easily drawn into the thin wires because it is also very ductile. Due to all these properties Nichrome is used for making heating elements. These heating elements are electric heater, electric rod, electric iron etc.

Therefore, Nichrome is used to make heating elements like electric heaters, electric rod, electric iron etc.

Note:The working of heating elements that are used in electrical appliances is based on the fact that when a current is passed through a conductor, the resistance is produced in it. Due to resistance, heat is produced in the appliance. This is known as the heating effect of the electric current.