Electromagnetic Energy

Electromagnetic energy can be termed electromagnetic radiation. It is a common term used to describe the energies associated with electromagnetic waves. It is the energy that propels such waves to propagate through any medium. Electromagnetic radiation has no charge or mass, and it moves in a pack of light energy known as photons. Electromagnetic energy is one of the most significant entities in the universe. It is the entity that drives the electromagnetic waves.

Electromagnetic energy gets released when an external force accelerates an electrical charge. The acceleration generates a wave of alternating magnetic and electric fields that detaches from the charge and moves independently in the medium.

Electromagnetic waves are made of discrete packets of energy called photons. They carry a significant amount of energy through a medium or vacuum from one place to another. Electromagnetic radiation can transfer various levels of heat depending on the frequency and wavelength of the EM waves. This showed that electromagnetic radiations have wave properties and particle characteristics.

Mechanism of Electromagnetic Waves

Electromagnetic energy is the consequence of changing electric and magnetic fields. When a charged particle is stimulated by displacing it up and down, the electric field is changed. Thus, creating the above alternating electric field. The electric fields also generate magnetic fields. Variation of magnetic field happens when magnetic current is uniformly fluctuating. Electric fields and magnetic fields are mutually connected. When one quantity varies, the other does the same. The electric fields and magnetic fields move perpendicular to each other, which enables the polarised orientation of electromagnetic fields. A changing magnetic field produces a changing electric field, which in turn creates a changing magnetic field. The byproduct is a continuous chain phenomenon leading to transverse electromagnetic waves. The EM waves travel in carriers containing particles called photons. They do not have rest mass or charge, and they move at the speed of light. The combination of moving photons and electromagnetic coupling is responsible for the movement of electromagnetic radiation. Different states of photons and wave properties lead to different types of electromagnetic waves.

The video explains the fundamental concepts of electromagnetism.

Electromagnetic Spectrum

The electromagnetic spectrum is the range of all electromagnetic radiation in terms of its wavelengths and frequencies. Each form of wave and frequency pair generates different forms of energy. Electromagnetic frequency is equal to the number of wave crests that reach a particular point in a second. Hertz (Hz) is the measuring unit of frequency. It can be defined as one wave cycle per unit time or second. The unit term is named after physicist Heinrich Hertz who conducted the experiment for the comparison of the velocity of waves and the speed of radiation or light. He found that both the values are equal and almost identical in all other aspects. The speed of a wave is equal to frequency times the wavelength. When wavelength decreases, frequency increases simultaneously, and the more energetic the electromagnetic waves become. Electromagnetic wave energy is calculated in electron volts. It is the kinetic energy needed to transmit electrons through a volt potential. It is also the measurement of how much energy is required to produce more peaks or waves. The smaller the wavelength can be, the more energy the wave emanates. A longer wavelength has less energy and a lower frequency. The electromagnetic spectrum can be considered as a horizontal straight line. At the right end of the EM spectrum, lower frequency (hertz) radiation exists. At the left end, radiation with higher frequencies (hertz) and shorter wavelengths exist. The electromagnetic energy becomes more powerful when the frequency increases.

Radio Waves

Radio waves are low-frequency electromagnetic waves. It is present at the start of the electromagnetic spectrum. EM waves with longer wavelengths have the lowest frequency and consequently the lowest energy. Radio waves have many practical applications like media broadcasting, wireless communication, radio telescopes, etc.

Microwaves

The microwave is a type of electromagnetic wave with wavelengths within the range of one metre to one millimetre. Its corresponding frequencies range from 300 MHz to 300 GHz, respectively. Microwaves are extensively used in wireless networks, satellite and spacecraft communications, microwave radio relay networks, medical treatment, remote sensing, particle accelerators, radio astronomy, spectroscopy, etc.

Infrared Waves

An infrared wave or IR radiation is a region of the electromagnetic spectrum where wavelengths range from about 700 nanometers to 1 millimetre. Infrared waves are much longer wavelengths than those of visible light but shorter wavelengths than those of radio waves. A range of IR radiation can be easily detected as heat. The infrared section can be further divided into far-infrared, mid-infrared, and near-infrared. Far infrared is also known as thermal infrared. They are used to detect, locate and view bodies in space. Infrared waves allow us to track and monitor the Earth’s temperature patterns. They are also used for thermal imaging and the most remote controls of digital devices.

Visible Light

Visible light is located in the middle of the EM spectrum. It is the section of the electromagnetic spectrum that is optically visible to the human eye. Every form of electromagnetic light is counted as light, but since this EM radiation is the only light optically visible to human eyes, it is known as visible light. A rainbow is a type of visible light where each rainbow colour has different wavelengths. The red has the longest wavelength, and the violet has the shortest wavelength.

Ultraviolet (UV) Waves

Ultraviolet waves are electromagnetic waves with wavelengths ranging from 10 nm (30 PHz) to 400 nm (750 THz). They are much shorter than visible light and longer than X-rays. UV waves are present in sunlight. They also constitute around 10% of the total EM radiation emanating from the Sun. Ultraviolet waves have a shorter wavelength and greater energy. They are placed on the higher frequency spectrum end. Ultraviolet light could damage or harm the skin as it might cause sunburn and even affect the human DNA.

X-Rays

X-ray or X-radiation is a high-energy form of electromagnetic radiation. Generally, they have a wavelength extending from 10 picometers to 10 nanometers with respective frequencies ranging from 30 petahertz to 30 exahertz. The inherent energy ranges from 145eV to 124 keV. X-rays wavelengths are much shorter than Uv radiation and usually longer than those of gamma radiation. The body temperature influences X-ray wavelength. Hotter the body, the shorter the wavelengths. They are famous for their application in medical imaging. They are used to produce sharp monotone images of objects on X-ray films. Images are formed when X-ray radiations are shot through a body part. X-radiations can be dangerous when living beings are subjected to excessive exposure. This is the reason why patients wear protective gear while going through an X-ray machine.

Gamma Rays

A gamma-ray (gamma radiation) is a piercing type of electromagnetic radiation emanating from the radioactive disintegration of subatomic nuclei. It is made of the shortest wavelength EM waves, with frequencies above 30 exahertz. It is placed at the end of the spectrum. Gamma-ray has the highest energy frequency. Due to these characteristics, gamma radiations are the most powerful EM waves. Gamma radiations are produced from nuclear reactions, nuclear decays, stellar explosions, etc.

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