Electromagnetics or Electromagnetism is a branch of Physics involving electromagnetic forces i.e. dealing with concepts and interactions of the electric and magnetic field.
Physics recognizes the existence of three or four qualitatively different forces to explain the behavior of the natural world. Electromagnetics is concerned with one of these forces.
The importance of the Electromagnetism is realized every day through telecommunication and electrical power systems. But the significance of Electromagnetics is not confined to obvious everyday manifestations. The structures, properties, interactions of the smallest unit of the world i.e. atom are also explained by electromagnetic forces. Electromagnetism accounts a greater part of Physics of all the subject areas.
History of Electromagnetics
The roots of Electromagnetics are way back in the history. The ancients had an acquaintance about substances like amber which when rubbed attracts lightweight objects. People were also aware of the effects of electricity in form of lightning. But these things remained merely interesting and mystifying phenomena over the period of time.
In the middle ages, many scientists had notable works related to electricity. Dr. Willian Gilbart, Robert Boyle, Otto von Guericke, Sir Thomas Browne are worth mentioned in relation to it.
Orsted noticed a compass needle deflected away from magnetic north when the current from the battery he was using was switched on or off. He proposed that electric current produces a magnetic field. This was a breakthrough finding for electromagnetics and resulted in intensive research throughout the scientific community in electrodynamics.
Ampere developed a mathematical model to represent the magnetic forces between current-carrying conductors. Faraday gave an account for electromagnetic induction.
Initially, electricity and magnetism were considered to be two separate forces. this view changed with Maxwell’s Theory which is considered as a mother of electromagnetic theory. James Clerk Maxwell presented the work related to Electromagnetics with clearly demonstrated by experiments.
Applications of Electromagnetism
Electromagnetic principles have numerous applications in various allied disciplines such as microwaves, antennas, electric machines, satellite communications, bioelectromagnetics, plasmas, nuclear research, fiber optics, electromagnetic interference and compatibility, electromechanical energy conversion, radar meteorology, remote sensing etc.
Most of the household appliances work on the principle of electromagnetism. Fans, blowers, cooling systems etc run the motors which are based on electromagnetic induction. Many of the kitchen appliances for example. microwave ovens, induction cookers, mixers etc are based on the Electromagnetic theories. Television, radio, stereo systems etc posses EM theory incorporated in many of the functional parts.
We can not imagine any industrial appliance without the Electromagnetism. Generators and motors which are the prime factors of any industrial application are solely based on EM principles. EM fields are used in induction heaters for melting, forging, annealing,
surface hardening, and soldering operations.
The modern communication system rests on the EM waves. For long-distance propagation of the message signal, EM waves act as a carrier signal. Waveguides, transmission lines, antenna etc. use principles of electromagnetism.
EM power is also used in physical medicine. For example, shortwaves or microwaves, are used to heat deep tissues and to stimulate certain physiological responses in order to relieve certain pathological conditions. RF range frequencies are mostly used in medical applications like MRI.
EM energy offers many new and exciting possibilities in agriculture. It is used, for example, to change the vegetable taste by reducing acidity.