Question

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

Answer 1

Hint: Here, we will proceed by discussing the electric heaters. Then, we will explain the working principle of an electric heater. Finally, we will write down the reason for the glowing of the heating element of the heater.

Complete step-by-step answer:
Today a wide variety of heaters are available on the market. Whilst some of the same concepts apply to most heaters, there are slight differences in each make and model. While many furnaces are powered by coal, oil, or other fossil fuels, smaller heaters mostly rely on electrical power. The electrical resistor is the primary component common to all electric heaters.

When you turn on a heater, the electrical current generated heats up the components of the nichrome wire (best known as the heating coils) within the device. When the current passes through the resistor electrical energy is converted into heat. That is why electric heaters are also known as heating units for resistance.

The next step in the heating process depends on whether or not the heater has an electric fan built on it. It can help bring cool air into the radiator if there is a fan. The air moves through the heating elements and is then pushed back into the room that's close to how hair dryers operate. This is also called convection heating since the heat is transferred through the air. Convection heaters provide a good way to quickly warm up a space by getting hot air flowing around the house. If the heater has no fan, air reaches the device from the below. The air flow passes through the coils, is heated and eventually makes its way out at the top of the device.

An electric heater works on the principle of the electric current's heating effect. The heater's heating element blocks the electric current and will not let it through. The heater's heating element consists of an alloy that has very high resistance, so that when the current flows through the heating element it becomes too hot and glows red. The heating element does not melt due to their high resistivity. But the cord's resistance where the cord is normally made of copper or aluminium is very small so it doesn't glow. The electric heater's cord is a good electricity conductor so it doesn't get hot and doesn't glow either.

Note: Direct heating, as the name implies, is a heating method by which the heater is directly immersed in the medium to be heated (depending on the manufacturing process, it may be liquid or gas). It is the most effective heating process, since there is no loss of heat transfer or thermal lag. Indirect heating is based on the basic concept of the transfer of heat from the hotter to the colder medium. The system does not directly use electric heaters.