Magnetism Definition and Theory
Magnetism refers to a phenomenon upon which a force of attraction comes up between the electrically charged particles which are in motion it is the force which causes a paper clip or nail to be pulled towards the magnet.
Electric forces are initiated within motionless electric charges, therefore magnetic and electric forces do present in the motion electric charges. Magnetic force which is normally found in between 2 moving electric charges is referred to as the force that is initiated on an individual charge by a magnetic which is created by the other. This kind of force is zero in case the second charge is traveling towards the direction of the magnetic field because of the first and is the greatest in case it travels at right angles with the magnetic field. The force of magnetism is usually responsible for the action of an electric motors and the attraction the attraction that exist between the iron and the magnets. (Blarney 2003).
In the field of physics, magnetism refers to one of the ways through which objects exert repulsive or attractive forces on some other objects. One of the world well renowned objects which have been shown to comfortably exhibit magnetic properties which are reliable include iron and its known alloys such as nickel and cobalt. All of these objects are usually influenced to a lesser or greater extend by the presence of a magnetic field. Magnetism is one the components of electromagnetic waves, for instance, light (Arthur, 1998).
Qualitative Explanation of Magnetism
By its nature, every electronic is a small magnet. The high numbers of electrons that are countless in number are usually randomly oriented in various directions, therefore leaving no single effect on average. But within a magnet, electrons seem to face the same direction; therefore they all pull towards each other, creating a totally strong magnetic force (Edward, 2007).
One of the most acknowledged theory of magnetism which takes into account the basic collection of molecular of the material. This is known as the Webber’s theory. This particular theory takes the basic assumption that the entire well known magnetic objects usually comprise of significantly small molecular magnets. Any given form of material that is not magnetized posses the forces of magnetism of its molecular magnets which are neutralized by the molecular magnets that are adjacent, hence eliminating any form of magnetic effect. Any magnetized material will always have more of the molecular magnets lined to enable the north pole of each single molecule to point in one direction while the south pole to face the opposite direction. Thus, a material with its molecules aligned will consequently have a single effective north pole and one other effective south pole. A steel bar can be easily magnetized by several round of stroking. This condition of magnetization can be accomplished by stroking a bar for a number of times strictly following adherence to same direction using a magnet. Therefore the force of magnet coming from the north pole of the magnet that is being used causes the molecules to align themselves (Lillian, 2004).
One of the recent theories of magnetism is based on the principle of electronic spin. With the use of inferences from what is observed in the atomic structure, it is found out that matter is found to consist of significant number of atoms of which each of them consists of one or more small orbital. These electrons are assumed to orbit in a number of shells and also sub-shells and this depends upon the distance between them and the nucleus. The analysis of the atom’s comprehensive structure is originally to the major and massive solar system, in that the electrons arranged on the several orbits are the planets arranged on the axis and the sun being the major initiator of the energy and force that holds the planets in place and can symbolize the nucleus. With the clear movement that is done on the orbits by the atoms they also do rotate and vibrate on the specific place of there attachment on the orbits. It is also therefore a belief that the electrons revolve on its axis when it orbits the nucleus of a given atom.
The experiment has proven that an electron possesses a magnetic field about it together with an electric field. The expected efficiency of the electron field which contains a magnetic field in totality together interrelates with each other and the electric force is a result of the magnetic field being split. Hence the efficiency of a magnetic field of an atom can hence be clearly found out by using the amount of electrons that spin on each and every one direction. In case an atom has the same number of electrons that are spinning in the opposite direction then the magnetic fields that6 surround the electrons are able, to cancel hone another and the atom is then the atom loses its magnetism. But if more electrons are able to spin in a given single direction compared to the other, the atom is magnetized. Taking a precise example, let us say an atom which has numbers 26 as its atomic number which is iron has also twenty six protons in its nucleus plus the twenty six revolving atoms on its orbital. Hence it follows out that if you consider thirteen electrons spin in a direction say clockwise then another thirteen electrons spin in the anticlockwise direction, the opposing magnetic fields will be fully neutralized.
Theory of Magnetism
In case a magnetic piece of still is divided into two through cutting, and then each piece is already a magnet with a South or North Pole. For this reason one can say that a magnet is made up of very many “tiny” magnets that are all lined up with their N poles that point towards the same direction. The given ends of any magnetic usually are known to out way and repel each. This therefore confirms that the poles of the magnet are around the ends (Jacob, 2000).
In a bar that is not magnetized, the “tiny” magnets that point towards all the directions, the N pole of one is neutralized by another’s S pole. The end effect is that the magnetism swaps out and hence there will be resultant free poles near the ends (Steven, 2005).
The theory tries to explain the breaking of the limit of a magnet to magnetic strength demagnetization.
Destroying Magnetism
It is not hard to destroy a magnet. Little magnetic domains do exert force on each other which makes them change their alignment. It is only in special cases, for instance iron whiskers. The forces are able to push the domains towards lining up so that they cancel the long range of the magnetic field. The domains stay together in a good network for a long time and this enables the fields to add up together. Heating up or even dropping the magnet down will partially or completely cause demagnetization. Hammering is yet another way of destroying a magnet
Differences between Magnetic and Electric Measurement
Magnetic and electric forces are always part of one physical phenomenon. Electric and electromagnetic forces that are understood by one observer are understood by a different observer in a different frame of reference in form of a mixture of magnetic and electric forces
How to do magnetic field measurement for small frequency and high frequency for different types of antennas, for switching power supply, for c.p.u, for a motherboard using magnetic field probe, vector analyzing network or spectrum analyzer for these measurements, if possible put block diagram and circuits. (Eugine 2003)
An identifier of the amount of voltage linked to the toroidal antenna which is used to find out an induced amount of voltage which is comparative to a constituent of an electric field that is at right angles to the plane of the toroidal antenna in the middle of it. The toroidal component comprises; toroid, a continuous multi-turn uniform that winds around the toroid, the detector of the voltage that is connected to the winding for the purpose of detecting voltage induced by a magnetic field that is time-varying which is associated with the time-varying electric field (Carlton, 2004).
Information about Vector Analyzing Network and Spectrum Analyzer for These kind of Measurements
Measurement Performance
An agilent 4396A or HP 4396A Spectrum or Network analyzer provides a good RF Vector network, spectrum and optional impendence measurement for the lab and applications Gain, phase, group delay, distortion, spurious, CN, and noise measurements are often required to be used for evaluating components and circuits which can be measured using one instrument. If combined with a test set, the 4396A provides reflection measurements, for instance, return loss, SWR, and S parameters. As a vector network analyzer, it operates from 100 kHz to 1.8 GHz with 1 mHz resolution and it’s integrated synthesized source provides -60 to +20 dBm of output power with 0.1 dB resolution. As a spectrum analyzer, this unit operates from 2 Hz to 1.8 GHz with resolution bandwidths spanning 1 Hz to 3 MHz in a 1-3-10 sequence. A fully synthesized local oscillator allows stable and accurate frequency analysis.
Wide Dynamic Range
The dynamic range which is together with sweep rate of the HP 4396A in any given measurement of the network mode are usually very vital features. Over 110-dB dynamic range is always a guarantee and specifically more than a 120-dB dynamic range is usually attained. These dynamic ranges that are wide can be got when a high sweep range is attained. (Rarta 2005).
The Future Demand for the Measurement and How It Could Be Effected
Improving RF Measurements through Vector Analysis
For signals of the broadband to be captured, it is always important to change from the equipment of the narrowband measurement to a vector instruments. When choosing a vector instrument to be used to measure broadband signal, it is always important to put into consideration the DUT bandwidth together with all factors of measurements. (Geoffrey, 1993).
To add on capturing broadband signals, the vector instruments can be used to deliver some other important merits to the measurement application. While performing spectral sweeps or any other forms of measurements that span wider ranges of frequency and a wide real-time bandwidth of the vector analyzer can systematically raise the test time. (Lurkel 2003).
In any given general purpose acquisition of a spectrum, instrument of the vector allows faster acquiring and measuring times than the scalar instrumentation. The vector instrument is able to capture phase, frequency information and amplitude. On the other hand, traditional instrumentation may not be able. This vector capability can be used to capture and display time and frequency information, which is important in performing a joint analysis of time-frequency as well as displaying 3D spectrograms or waterfall plots. One can also be able to use phase information in conjunction with vector instruments in I/Q or modulation analysis to assist in eliciting of a very much detailed view of the signals that are likely to be under analysis. The traditional benefits, as indicated, are able to make a vector instrument even more flexible and more powerful than any other traditional analysis of narrowband spectral (Mathew, 2006).
References
Arthur, J and Brennan, S. (1989) Magnetic Field Lines, Naval government press (8) 6-9.
Blarney, M. (2003), Magnetism and the effects to the electronic shell. Longman publishers (2) 22-26.
Carlton, V (2004), Magnetism, Smart motor Publication, (4) 1-8.
Edward, P. (2007). Electromechanical Devices: Analysis and Applications, Academic Press.
Geoffrey, N. (1998). Symbols in Physical Chemistry, Oxford: Blackwell Science.
Jacob, N. (2000), Electromagnetism, power and energy journal, (2) 2-7.
Lillian, S. (2004). Magnetism and magnetic application, Inc. Science Journal.
Lurkel. B. et al., (2003) The Insertion Device Magnetic Measurement, Macmillan Publishers (8) 5-11.
Mathew, C. (2006), The Measurement of Magnetism, 5th edn, Melbourne University Press (12) 34-41.
Rarta, M. (2005) Magnetic fields and forces, Applied Physics journal.
Steven. P. (2005) Magnetic monopoles, New Jersey: Maxin publishers (7) 3-9.
Eugine, P. (2003) Magnetism, Access, vol. 5, no.3, pp. 6-10.