Radio is one of the most effective means of sending messages, news, music, etc. to distant places. In this process, radio waves are used, which are a type of electromagnetic waves.
The credit of inventing radio goes to Gugliemo Marconi of
. In 1901, Marconi succeeded in sending radio from Italy to Newfound land. England
The frequency of the radio waves used in radio broadcast lies between 150 kilohertz and 30,000 megahertz. The messages are transmitted through a transmitter which is connected to the radio station. Transmitter consists of instruments like microphone, modulator, amplifier, oscillator, antenna, etc. the person in the radio station speaks in front of a microphone, which converts sound waves into electrical signals. These signals are mixed with carrier waves in a modulator, amplified and transmitted.
The modulation of radio waves is of two types; amplitude modulation and frequency modulation. The messages transmitted by transmitter are received by the aerial of our radio set. A radio set converts the electrical signals into sound and we hear the original programmed.
Radio is used in telecommunications, navigation, etc. the radio services started in 1936 in our country. Today, there are more than 100 radio stations in our country.