What Is Frequency? Hertz, Waves and AC Electricity

Automatically transcribed from the original recording. Small transcription errors may remain.

Imagine you're at a rock concert and feeling the bass thumping through your body. That thumping sensation, that vibration, is caused by frequency, or how often something happens in a certain period of time. So in the case of music, it's how often the sound waves are vibrating. But frequency isn't just for music. It also applies to electricity. So when you plug something into a wall, electricity flows through the wires at a certain frequency, measured in Hertz. And this measures how many times per second the electricity changes direction. And it's named after a man named Heimrich Hertz, who helped us understand the properties of

electromagnetic waves. So speaking of waves, they're just basically disturbances that travel through a medium like air, water, or even space. So electromagnetic waves are unique because they can travel through the vacuum of space, unlike ocean waves or sound waves that require a medium to travel through. And these waves are responsible for all forms of light, radio waves, x-rays, and even cosmic rays. So how does this tie in with the electricity that powers our homes and businesses? Well, in the United States, we use a voltage of 120 volts and a frequency of 60 hertz to provide

a strong constant flow of electricity, like a river rushing downstream. In contrast, Europe uses a voltage of 220 volts and a frequency of 50 hertz to provide a slower but more consistent flow of electricity, like a gentle stream that never dries up. Now the reason for these differences in voltage and frequency lies in the way electricity is generated and transmitted. Power plants and generators in the United States are designed to rotate at a speed that produces an alternating current frequency of 60 hertz, while those in Europe are designed to produce an AC frequency of 50 hertz.

So alternating current periodically reverses direction, making it efficient for transmitting over long distances and easily transformed to different voltage levels, making it the most commonly used form of electricity in the world. So why do we use different voltages and frequencies? Well, it all goes back to history and tradition. So in America, we started using 120 volts back in the late 1800s when electricity was first being used to power homes and businesses. At that time, it was the most efficient and cost-effective way to provide electricity to the masses.

Now in Europe, they started using 220 volts in the early 1900s when electricity was becoming more widespread and we understood more about it. So why does this all matter? While some devices like clocks rely on the frequency of electricity to keep accurate time. If you travel to another country and notice that your clock is running fast or slow, it's likely because the frequency of the electricity is different than what your clock was designed for. In fact, some older clocks and appliances may not work at all if the frequency is not correct. But it's not just about clocks.

the frequency of electricity can affect the performance of motors, generators, and other electrical devices. And in some cases, it can even be a matter of life and death. Like heart monitors and ventilators must be designed to work with the frequency of the electricity in the country where they are being used. So while Hertz may seem like a small detail, it's actually a crucial component of the electrical systems that power our world. Whether it's keeping time, running machinery, or saving lives, Hertz is a beat that we all need to keep in tune with.