Electromagnetic Field Essay

818 Words 4 Pages
Electromagnetic Energy Storage Electromagnetic energy is a form of energy stored in electromagnetic fields. An electromagnetic field refers to the physical field produced by charged objects. The field is due to the interaction of electric and magnetic fields which oscillate in perpendicular directions to one other and perpendicular to the direction of wave and energy propagation. Electric field is produced by stationary electrical charges while the magnetic field is as a result of moving electrical charges (Hauss and Melcher 20). The particular way in which charges and electrical currents interact with the electromagnetic field are described by Maxwell 's equations, Lorentz force law among other useful relations (Chegg 9). Electromagnetic …show more content…
For an electric field, the total energy density which is given by energy stored per unit volume can be determined to be . Where the symbols assume their scientific meaning, this relation is useful in the evaluation of the total energy stored in a capacitor. An inductor is a coil of electrical wire with parameters that enable it to store energy in the form of the magnetic field (David, 1989). The magnetic field energy density is given by . This energy density is useful in the determination of energy stored in the Inductor. Both the electric and magnetic fields play important roles in energy transport as described by the pointing vector (Mats and Jonsson 23). It is however important to notice that the energy associated with magnetic and electric fields is equal and therefore the use of one the equation above can be used to represent the other. It is also important to realize that for an electromagnetic wave with particular energy, the electric field is directly proportional to the energy of “the magnetic field with a constant of proportionality equal to the speed of light” (Mats and Jonsson …show more content…
This law forms the basis of operation of electrical generators and electrical motors (Chegg 32). The energy stored by a coil carrying current is given by half the inductance of the coil multiplied by the square of the current. Solenoids used in some electrical appliances is a typical example of a coil that stores electromagnetic energy. The energy stored in the solenoid is mainly a function of the coil dimensions, the number of turns of the solenoid and the amount of current flowing through the coil. In addition, there are three main properties that determine the design and shape of a coil for it to store a sufficient amount of electromagnetic energy. First strain tolerance which is important not only because of its electrical effect, but because it determines how much material is required to keep the coil from breaking (Hauss and Melcher 5). This is the reason a toroid is preferred to the linear solenoid. The second property is thermal contraction upon cooling affected by the size of the energy stored in the coil and also during operation. Lastly, the Lorentz forces in the charged coil. The Lorentz forces refer to the combination of electric and magnetic forces on a point charge due to the presence of electromagnetic

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