Caffeine Information. Caffeine is naturally found in cocoa beans, coffee beans and tea and is synthetically produced for use in certain medications and in beverages. This substance is a stimulant drug that quickly enters the bloodstream and affects the brain.
Frequency Range Chart. The radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz.Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.he radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz. Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.
An audio frequency (abbreviation: AF) or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human. The SI unit of audio frequency is the hertz (Hz). It is the property of sound that most determines pitch. The generally accepted standard range of audible frequencies is 20 to 20,000 Hz, although the range of frequencies individuals hear is greatly influenced by environmental factors. Frequencies below 20 Hz are generally felt rather than heard, assuming the amplitude of the vibration is great enough.