How is heat produced in electric heating?

Heat is produced in electric heating through the process of resistance. When an electric current flows through a conductor, such as a heating element, the electrons moving through that conductor encounter resistance, which impedes their flow. This resistance causes energy to be dissipated in the form of heat, according to Joule's Law. The amount of heat generated is directly proportional to the square of the current multiplied by the resistance (H = I²R), where H is the heat produced, I is the current, and R is the resistance.

In contrast to the other choices, the correct answer demonstrates the fundamental principle of electric heating. Other options suggest mechanisms that do not effectively describe the physics of electric heat generation, such as freezing electrons or the repulsion and attraction of electrons, which do not contribute to the heating effect in this context. The understanding of how resistance in a conductor generates heat is crucial for HVACR professionals when designing and troubleshooting electric heating systems.