Introduction
The electromagnetic spectrum encompasses a wide range of radiation emitted by stars, such as our sun. Waves of electromagnetic radiation commute through space. The frequency of a wavelength explains the no of waves/second it generates. Wavelength is the size of a wave in meters. At one end of the spectrum, radio waves with the lengthiest wavelengths and least frequency exist. One radio wave can travel the length of a football field. Among all electromagnetic waves, radio waves have the greatest size and lowest energy, whereas visible light is measured in inches. In this article we will learn about the electromagnetic spectrum, radio waves, generating radio waves, properties of radio waves, uses of radio waves, effects of radio waves, and some FAQs.
Electromagnetic spectrum
The electromagnetic spectrum encompasses a wide range of radiation emitted by stars, such as our sun. Waves of electromagnetic radiation commute through space. The frequency of a wavelength explains the no of waves/second it generates. Wavelength is the size of a wave in meters. At one end of the spectrum, radio waves with the lengthiest wavelengths and least frequency exist. One radio wave can travel the length of a football field. Microwaves, which have smaller wavelengths and high frequency than radio waves, produce more energy. Microwaves are used in cellphones, radar, and microwave ovens.
Then there’s infra-red ray. The infrared signal is generated by the sun, fire, living creatures, and other heat sources. Visible light is located in a narrow band of the electromagnetic spectrum between infrared and ultraviolet light.
The least frequencies and lengthiest wavelengths of visible light are found in red wavelengths. Wavelengths considerably become shorter and frequencies increase as we proceed from red to violet. and visible frequencies to ultraviolet frequencies. When exposed to ultraviolet light, human skin generates vitamin D. However, too much ultraviolet light causes sunburn. Then there are x-rays, which can pass via soft tissue but not higher-density materials like bone, making them useful for medical tests. X-rays are also used for security purposes, such as airport luggage checks. Gamma rays have even shorter wavelengths, higher frequencies, and higher energy levels. In contrast to radio wave wavelengths that are the size of a football field, gamma-ray wavelengths are the size of atom nuclei.
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Radio waves
Among all electromagnetic waves, radio waves have the greatest size and lowest energy, whereas visible light is measured in inches. A radio wave can be as short as 19 cm (the length of a water bottle) or as long as cars, ships, mountains, and even as long as our planet itself. In 1888, Heinrich Hertz discovered radio waves. Some researchers require massive antennas to detect weak long-wavelength radio waves from space.
Properties
- These waves are generated by accelerated or oscillating charge
- These wave does not require any material/medium for their propagation.
- It is propagating in free space with the speed of light Le 3×10 m/s
- The amplitude of the Electric field and magnetic field are related to each other by the formula.
- The Cross product of the Electric field and magnetic field tells us the direction of propagation of waves.
- The direction of magnetic and Electné fields are always perpendicular to each other.
- The Speed of Electromagnetic waves in the medium is less than the speed of light in vaccum.
Generation of Radio Waves
The radio waves from the basic building blocks of radio communications. They are generated with the help of a transmitter and a receiver is used for the detection.
When a charged particle is accelerated, a radio wave is generated. There are various natural sources of radio waves like various stars, and dust clouds. As a part of black body radiations, all likes of warm objects radiate high-frequency radio waves, also called microwaves. These radio waves can also be generated through artificial means.
This can be done by a time-varying electric current. The time-varying current consists of electrons that are moving back and forth. So when this oscillating electric current is applied to an antenna, the power gets radiated as radio waves. These radio waves are transmitted through the atmosphere, getting reflected or scattered by various natural or artificial reflectors.
The radio transmitters use this antenna for sending energy into space, where a detector is placed that picks up this energy using another antenna attached to it. These radio transmitters and receivers are usually designed in such a way that they can only operate over a limited range of frequency which can be between 3 kilohertz to 300 gigahertz.
Applications of radio waves
Radio Waves are used for −
- Transmission of data and wifi
- Transmitting sound and television signals
- Global satellites communications
- Digital broadcast radio
- Radar navigation
Effects of Radio Waves
Mobile phone Radio Waves May Instigate Brain Tumors And Even Cancer. Openings To Radio Waves Have Been Unofficially Linked To Sleep Disorders, Headaches, And Other Neurological Problems.
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