# Frequency & Sine 101

## Frequency & Sine 101

Bryan with HVAC School introduces the topic of Frequency & Sine 101. In doing so, he presents some easy ways to wrap your head around alternating current, electromagnetism, frequency, wavelength, and sine.

When we talk about electromagnetism, we’re referring to the relationship between electricity and magnetism; magnetism can generate electron flow, and electron flow can generate magnetism. A motor is a spinning electromagnet that generates electricity and has a rotational field; a sine wave represents the motor’s circular motion of the motor on a timeline rather than a circle.

You can metaphorically imagine electromagnetic waves as what happens when kids use a jump rope. The jump rope spins instead of just moving up and down; you SEE it moving up and down, but the actual movement is rotational. If the kids move it slowly, the wavelength is longer, and if the kids move it quickly, the wavelength becomes shorter; there are more peaks and valleys in the same period of time. Having more cycles means that we have a shorter frequency.

These wavelength and frequency principles also apply to microwaves, gamma waves, and even sound waves. Electromagnetic waves exist on a spectrum; we can only see visible light, but we also have radio waves and microwaves (longer wavelengths) and x-rays and gamma rays (shorter wavelengths) in our world. When you tune a radio, you tune it to the same frequency as the channel you’re looking for. The frequencies resonate, and the sounds from the radio wave source play on your radio.