Hertz (Hz, MHz, GHz)
Hertz (Hz) is the unit of frequency in the International System of Units (SI) and is used to measure the number of cycles per second of a periodic phenomenon, such as an oscillating wave or a vibrating object. The unit is named after the German physicist Heinrich Hertz, who made significant contributions to the field of electromagnetism.
One hertz (1 Hz) represents one cycle per second. As the values of frequencies can vary greatly, prefixes are often used to indicate larger units of frequency:
- Kilohertz (kHz): 1 kilohertz is equal to 1,000 hertz (1 kHz = 1,000 Hz). Kilohertz is commonly used to measure audio frequencies, such as those produced by musical instruments or the human voice.
- Megahertz (MHz): 1 megahertz is equal to 1 million hertz (1 MHz = 1,000,000 Hz). Megahertz is often used in the context of radio frequencies and wireless communication, such as FM radio broadcasting or Wi-Fi networks.
- Gigahertz (GHz): 1 gigahertz is equal to 1 billion hertz (1 GHz = 1,000,000,000 Hz). Gigahertz is typically used to describe the frequency of microprocessors, such as those found in computers and smartphones, as well as high-frequency communication systems, such as radar and satellite systems.
It is important to note that hertz only measures the frequency of a wave or oscillation, not its amplitude or energy. In the context of electromagnetic waves, higher frequencies correspond to shorter wavelengths and higher energies, while lower frequencies correspond to longer wavelengths and lower energies.
In summary, hertz (Hz) is the unit of frequency in the International System of Units (SI) and is used to measure the number of cycles per second of a periodic phenomenon. Kilohertz (kHz), megahertz (MHz), and gigahertz (GHz) are larger units of frequency, used to describe audio frequencies, radio frequencies, and microprocessor frequencies, respectively.