Back to Top Electromagnetic waves characteristics are similar to transverse waves. If the particles at a medium vibrate at right angles to the direction of the propagation of the energy then that wave is called as transverse wave.
The applications of the electromagnetic spectrum in daily life begin the moment a person wakes up in the morning and "sees the light. Since the beginning of the twentieth century, uses for other bands in the electromagnetic spectrum have proliferated.
At the low-frequency end are radio, short-wave radio, and television signals, as well as the microwaves used in cooking. Higher-frequency waves, all of which can be generally described as light, provide the means for looking deep into the universe—and deep into the human body. Yet, the Roman understanding of electricity did not extend any further, and as progress was made in the science of physics—after a period of more than a thousand years, during which scientific learning in Europe progressed very slowly—it developed in areas that had nothing to do with the strange force observed by the Romans.
The fathers of physics as a serious science, Galileo Galilei and Sir Isaac Newtonwere concerned with gravitation, which Newton identified as a fundamental force in the universe. For nearly two centuries, physicists continued to believe that there was only one type of force.
Yet, as scientists became increasingly aware of molecules and atoms, anomalies began to arise—in particular, the fact that gravitation alone could not account for the strong forces holding atoms and molecules together to form matter.
At the same time, a number of thinkers conducted experiments concerning the nature of electricity and magnetism, and the relationship between them.
Among these were several giants in physics and other disciplines—including one of America's greatest founding fathers. In addition to his famous and highly dangerous experiment with lightning, Benjamin Franklin also contributed the names "positive" and "negative" to the differing electrical charges discovered earlier by French physicist Charles Du Fay InFrench physicist and inventor Charles Coulomb established the basic laws of electrostatics and magnetism.
He maintained that there is an attractive force that, like gravitation, can be explained in terms of the inverse of the square of the distance between objects.
That attraction itself, however, resulted not from gravity, but from electrical charge, according to Coulomb. A few years later, German mathematician Johann Karl Friedrich Gauss developed a mathematical theory for finding the magnetic potential of any point on Earthand his contemporary, Danish physicist Hans Christian Oerstedbecame the first scientist to establish the existence of a clear relationship between electricity and magnetism.
This led to the foundation of electromagnetism, the branch of physics devoted to the study of electrical and magnetic phenomena. This theory shows how an electrical current in one coil can set up a current in another through the development of a magnetic field.
This enabled Faraday to develop the first generator, and for the first time in history, humans were able to convert mechanical energy systematically into electrical energy. A number of other figures contributed along the way; but, as yet, no one had developed a "unified theory" explaining the relationship between electricity and magnetism.
Maxwell had thus discovered a type of force in addition to gravity, and this reflected a "new" type of fundamental interaction, or a basic mode by which particles interact in nature.
Newton had identified the first, gravitational interaction, and in the twentieth century, two other forms of fundamental interaction—strong nuclear and weak nuclear—were identified as well. In his work, Maxwell drew on the studies conducted by his predecessors, but added a new statement: This statement, which did not contradict any of the experimental work done by the other physicists, was based on Maxwell's predictions regarding what should happen in situations of electromagnetism; subsequent studies have supported his predictions.
Electromagnetic Radiation So far, what we have seen is the foundation for modern understanding of electricity and magnetism. This understanding grew enormously in the late nineteenth and early twentieth centuries, thanks both to the theoretical work of physicists, and the practical labors of inventors such as Thomas Alva Edison and Serbian-American electrical engineer Nikola Tesla But our concern in the present context is with electromagnetic radiationof which the waves on the electromagnetic spectrum are a particularly significant example.
Energy can travel by conduction or convection, two principal means of heat transfer. But the energy Earth receives from the Sun —the energy conveyed through the electromagnetic spectrum—is transferred by another method, radiation. Whereas conduction of convection can only take place where there is matter, which provides a medium for the energy transfer, radiation requires no medium.
Thus, electromagnetic energy passes from the Sun to Earth through the vacuum of empty space. The connection between electromagnetic radiation and electromagnetic force is far from obvious.
Even today, few people not scientifically trained understand that there is a clear relationship between electricity and magnetism—let alone a connection between these and visible light.
The breakthrough in establishing that connection can be attributed both to Maxwell and to German physicist Heinrich Rudolf Hertz Maxwell had suggested that electromagnetic force carried with it a certain wave phenomenon, and predicted that these waves traveled at a certain speed.
In his Treatise on Electricity and Magnetismhe predicted that the speed of these waves was the same as that of light—, mikm per second—and theorized that the electromagnetic interaction included not only electricity and magnetism, but light as well.Electromagnetic Radiation of light in a vacuum.
Figure The electromagnetic spectrum. Waves • Waves have 3 primary characteristics: • 1. Wavelength: distance between two peaks in a wave. Symbol is 8 • 2. Frequency: number of waves per second that Electronic transitions in the Bohr model for the hydrogen atom.
6 R H = 2B2:e4/h2. Watch video · Now even if you ignore this particle aspect of light, if you just look at the wave aspect of the light, it's still fascinating. Because most waves require a medium to travel through. So for example, if I think about how sound travels through air-- so let me draw a bunch of air particles.
Antennas and its Applications Pramod Dhande Armament Research & Development Establishment, Dr Homi Bhabha Rd, Pashan, Pune the concept of antenna one should know the behaviour of Electromagnetic waves in free space. So I am briefly covering Electromagnetic spectrum. Figure 5. EM wave in free space.
4k audio spectrum simulation on white background use for music and computer calculating concept hd Group of happy girls running and playing in water at the beach on sunset. Beauty and joyful teenager friends having fun, dancing, spraying over summer sunset.
To represent this concept musically, the anthem’s score calls for a soloist, representing beings everywhere, to make music that goes from a state of greater to lesser entropy, as the larger orchestra tends toward greater entropy in the background.
Radio waves are at the lowest range of the EM spectrum, with frequencies of up to about 30 billion hertz, or 30 gigahertz (GHz), and wavelengths greater than about 10 millimeters ( inches).