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

The cord of an electric heater does not glow while the heating element does because the cord and the heating element are typically made of different materials with different electrical and thermal properties.

Material Selection:

» The heating element of an electric heater is intentionally designed to have a high electrical resistance and to generate heat when an electric current passes through it. This is achieved by using materials with high resistivity, such as certain alloys like nichrome.
» The cord, on the other hand, is usually made of materials with lower resistivity and is designed to conduct electricity with minimal loss. The primary function of the cord is to carry the electric current from the power source to the heating element.

2. Heat Generation:

» The heating element is specifically designed to convert electrical energy into heat. As a result, it heats up significantly when an electric current flows through it, and this heating causes it to glow.
» The cord, being designed for electrical conductivity rather than heat generation, is chosen for its ability to transmit electrical power efficiently without substantial heating.

3. Temperature Tolerance:

» The heating element is designed to withstand and operate at high temperatures. The material properties of the heating element allow it to reach the necessary temperatures for efficient heat generation without melting or deteriorating.

» The cord, however, is not designed to handle the high temperatures associated with heat generation. Using a cord material that could withstand the high temperatures of the heating element might not be practical or cost-effective.
In summary, the heating element and the cord are designed for different purposes and, therefore, have different material compositions and properties. The heating element is designed to glow and produce heat, while the cord is designed to conduct electricity efficiently without significant heat generation.