Question

Why does the cord of an electric kettle not glow while the heating element does?

Answer 1

Hint: The resistance of the material of the cord of an electric kettle is very low compared to the resistance of the heating element. So because of the high resistance, heating element material becomes very hot and glows whereas the cord does not glow.

Complete step by step answer:
We are given to find the reason why the cord of an electric kettle does not glow while the heating element does.Heating element converts electrical energy into heat through the process known as Joule Heating in an Electric kettle. The electric current passing through the element encounters resistance, which generates the heat.The heating element of an electric kettle is made up of an alloy (80% Nickel and 20% Chromium). This alloy has very high resistance compared to the cord. So when the current flows through this the heating element becomes very hot and therefore, it glows.The wires, which are made of copper or aluminum, used for making cords do not become hot normally and that is why they don’t glow. The amount of heat produced in a wire depends on its material, length and thickness. The heating element and the wires are made of different materials so that the heat produced is more for the heating element and less for the cord.Because of less resistance than the heating element, the cord does not glow.

Note: Using electric kettles, you can get hot water for your green tea, coffee, soups and instant noodles with the help of electricity. When the kettle is turned on, a large electric current flows through the heating element (coil). The coil has an electrical resistance. This resistance turns electrical energy into heat as it passes through the coil.