The electromagnetism it is an important branch of physics; its mission is to study electrical and magnetic phenomena by bringing them together in a single theory. The bases of knowledge in electromagnetism were established by the British Michael Faraday.
Time after James maxwell completed these investigations; It was thus possible to delineate four vector equations that relate the electric field, the magnetic field and their corresponding sources: these are known as Maxwell’s equations or laws.
Examples of electromagnetism
Examples of equipment or situations that are based on electromagnetism are given below:
- Kitchen microwave
- Transformers
- Magnetic card readers
- Pendrives
- MRI equipment for medical studies
- Microphones
- Planes
- Digital cameras
- Cell phones
- Thermometers
- Optical instruments
- Magnets
- Compasses
- Plates
- Ultrasound equipment
- Oscilloscopes
- Mass spectrometers
- Modems
- Tomographs
- Mammographs
Functions of electromagnetism
Electromagnetism deals with describing the physical phenomena macroscopic in which electric charges intervene, both at rest and in motion. It is clear, then, that it does not describe phenomena on an atomic or molecular scale; To do so in such a level of detail requires resorting to other disciplines, such as quantum mechanics.
It is known that electromagnetic waves They travel in a vacuum at the speed of light and they are capable of transporting energy through space. The amount of energy carried by an electromagnetic wave depends on its frequency.
- See more in: Applications of electromagnetism
Types of magnetic substances
Magnetic substances can be:
- Ferromagnetic. They are strongly attracted to magnets. For instance: iron, nickel and cobalt.
- Paramagnetic. They are weakly attracted to magnets. For instance: platinum and tin.
- Diamagnetic. They are slightly repelled by magnets. For instance: water, copper and gold.
Key concepts
- electric field. It is the space in which a charged particle is placed and experiences a force called “electric force”, that is, the region of space where the electric force acts.
- Magnetic field. It is the point in space where a charge placed there with a speed other than zero undergoes a lateral deflection due to a magnetic force. Magnetic force is always perpendicular to velocity. Another way to define the magnetic field is as a mathematical model of the interaction between electric currents and magnetic materials (magnets, iron, cobalt, among others).
- Electrical polarization. It expresses the density of the permanent or induced dipole electric moments in a dipole. It also expresses the density of the magnetic dipole moments that are magnetized by a metal.
- Magnetic moment. For example, if we have a magnet, its magnetic moment indicates the force that the magnet exerts on electric currents and the force that the magnetic field also exerts on them.
The application of electromagnetism
Electromagnetism has not only been crucial in the field of engineering, also in others such as medicine, construction, aeronautics and even biology.
Inside of medicine It is worth highlighting the magnetic resonance technique, which is based on the magnetic properties of certain nuclei of atoms, such as hydrogen.
Images by magnetic resonance They use electromagnetic waves between 3 KHz and 300 GHz and a powerful magnetic field. This allows them to create detailed images of organs and tissues within living things in a non-invasive and safe way since ionizing radiation should not be used.
Today this application is key for the diagnosis of vascular or musculoskeletal diseases.