Table of Contents
In physics, electromagnetic radiation (EMR) is made up of electromagnetic (EM) field waves that travel through space carrying electromagnetic radiant energy. Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays are all examples of electromagnetic radiation. Electromagnetic radiation is traditionally composed of electromagnetic waves, which are synchronised oscillations of electric and magnetic fields.
Electromagnetic radiation, also known as electromagnetic waves, is produced as a result of a periodic change in an electric or magnetic field. Different wavelengths of the electromagnetic spectrum are produced depending on how this periodic change occurs and the power is generated. Electromagnetic waves travel at the speed of light in a vacuum, which is commonly denoted by the letter c. The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation inhomogeneous, isotropic media, forming a transverse wave. A sphere is the wavefront of electromagnetic waves emitted from a point source (such as a light bulb). All of these waves are components of the electromagnetic spectrum. Electromagnetic waves are emitted by electrically charged particles as they accelerate, and these waves can then interact with other charged particles, exerting force on them. EM waves can transfer energy, momentum, and angular momentum away from their source particle and into the matter with which they interact. Electromagnetic radiation refers to EM waves that are free to propagate (“radiate”) without the continuing influence of the moving charges that produced them, having travelled a sufficient distance from those charges. The term “near field” in this context refers to electromagnetic fields that are close to the charges and currents that directly produced them, specifically electromagnetic induction and electrostatic induction phenomena.
Overview
Electromagnetic waves, or EM waves, are another name for electromagnetic waves. Electromagnetic radiations are made up of electromagnetic waves that are generated when an electric field collides with a magnetic field. Electromagnetic waves can also be defined as the combination of oscillating electric and magnetic fields. Maxwell’s equations, which are the fundamental equations of electrodynamics, are solved by electromagnetic waves. Electricity can be static, similar to the energy that causes your hair to stand on end. Static magnetism, as in a refrigerator magnet, is another type of magnetism. A changing magnetic field causes a changing electric field, and vice versa—the two are inextricably linked. Electromagnetic waves are created by changing fields. Electromagnetic waves, unlike mechanical waves, do not require a medium to propagate. This means that electromagnetic waves can traverse not only air and solid materials but also the vacuum of space. A charged particle, in general, generates an electric field. Other charged particles are influenced by this electric field. Positive charges accelerate in the direction of the field, while negative charges accelerate in the opposite direction. The magnetic field is created by a moving charged particle. Other moving particles are influenced by this magnetic field. Because the force on these charges is always perpendicular to their velocity, it only changes the direction of the velocity, not the speed.
As a result, the electromagnetic field is created by an accelerating charged particle. Electromagnetic waves are nothing more than electric and magnetic fields travelling at the speed of light c through free space. When a charged particle oscillates around an equilibrium position, it is said to be accelerating. If the charged particle’s frequency of oscillation is f, it produces an electromagnetic wave with frequency f. This wave’s wavelength is given by = c/f. Electromagnetic waves are a type of energy transfer that occurs in space.
DISPLACEMENT CURRENT
It is this current that comes into play in a region where the electric field (and thus the electric flux) changes over time. The displacement current can be calculated using
where
= absolute permittivity (or free space permittivity) and
= rate of change of electric flux.
The displacement current is greatest when there is a constant electric flux connected to a region. Conduction current is the current in an electric circuit that arises from the flow of electrons in the circuit’s connecting wires in a defined closed path.
MAXWELL’S EQUATION
Maxwell discovered that all of the fundamental principles of electromagnetism can be expressed in terms of four fundamental equations, known as Maxwell’s equations. They are as follows:
GAUSS’S LAW FOR ELECTROSTATICS
The total electric flux through any closed surface is equal to the net charge inside that surface divided by εo , according to Gauss’ law.
This law connects the electric field to charge distribution, stating that electric field lines begin with a positive (+ive) charge and end with a negative (–ive) charge.
This law’s differential form is
PROPERTIES OF ELECTRONIC WAVES
The oscillation directions of the E and B fields are perpendicular to each other and to the propagation direction. Transverse electromagnetic waves exist in nature. The electric and magnetic fields oscillate at the same frequency.
Electromagnetic waves travel at the same speed as light through a vacuum.
Because the energy density of an electric field is 
and that of a magnetic field is 
, the energy density of an electromagnetic wave is
, where E and B are the instantaneous values of the electric and magnetic field vectors, respectively.
The ratio 
Duality of Waves and Particles
The nature of light is explained by a modern theory that includes the concept of wave-particle duality. In general, the theory states that matter has a wave nature and a particle nature and that various experiments can be performed to bring out one or the other. Using a large mass object, the particle nature is more easily discerned. In the year 1924, a daring proposition by Louis de Broglie led the scientific community to realise that matter (e.g., electrons) also exhibits wave-particle duality.
Relativity’s Special Theory
The various experimental anomalies could not be explained by the simple wave theory by the late nineteenth century. One of these anomalies was at the centre of a debate about the speed of light. Unless the equations were modified in a way suggested by FitzGerald, Maxwell’s equations did not appear. Lorentz predicted by the speed of light and other EMR, or that speed would depend on the observer’s speed relative to the “medium” (called luminiferous aether) which “carried” the electromagnetic wave (in a manner analogous to the way air carries sound waves). The experiments failed to find any observer effect.
FAQs
Name the property of an electromagnetic wave that is affected by the medium through which it travels.
The velocity of an electromagnetic wave is a property that depends on the medium through which it travels. Other properties of the wave, such as frequency, time period, and wavelength, are determined by the source of the wave.
What do you call electric waves?
Light, electromagnetic waves, and radiation are all terms used to describe the same physical phenomenon: electromagnetic energy. This energy can be described using terms such as frequency, wavelength, or energy.
