The magnetic field is the region enveloping a magnet in which the magnet’s effect is experienced. Magnetic fields show how magnetic force is distributed in the area and inside the bodies in the field. The magnetic fields are created by the movement of electric charges and innate magnetic moments of the fundamental particles. It is directly connected with a core quantum property called spin. Electric fields and magnetic fields are mutually related; they are both the driving components of the electromagnetic force (one among the four basic forces of the Universe).
Magnetic fields are an incredibly useful byproduct of magnetism. They are used in various modern technologies and tools. Here are the five interesting uses of magnetic fields.
Magnetic Resonance Imaging
Magnetic Resonance Imaging (MRI) systems employ a combination of radio waves and magnetic fields to produce images of body parts such as the spine, joints, brain, heart, abdomen, etc. The photos produced are then analysed for potential defects and abnormalities. MRI devices use powerful rare earth magnets, which generate intense magnetic fields that drive protons in the body to align with the field ideally.
When a radio current is then forced through the subject, the protons are activated and disturbed out of equilibrium (pressuring against the force of the magnetic field). When the radio field is switched off, the MRI detectors are able to perceive the energy emitted as the protons realign with the existing magnetic field.
Electromagnetic Wave Propagation
Electromagnetic waves are pairs of varying magnetic and electric fields that carry electromagnetic energy from one place to another. The magnetic and electric fields linked with electromagnetic radiations are vectors perpendicular to each other. The direction in which the electromagnetic wave propagates is perpendicular to the two planes consisting of the magnetic and electric fields. Without these fields, electromagnetic waves do not exist.
An electric generator is an electrical device that transforms mechanical energy into usable electrical energy by applying the electromagnetic induction principle. A voltage difference is produced as an electric conductor moves in a magnetic field. This variation of voltage can be used to displace electric charges, thus, producing an electric current.
Electromagnetic induction occurs when the conductor is positioned between the varying magnetic fields. A voltage will be induced when there is an increase or decrease in the intensity of the magnetic field (the given conductor is perpendicular to the magnetic field). Electricity is produced by rotating a coil in a magnetic field. A copper coil closely wound onto a metal core is called a conductor coil. It is rotated briskly between the end poles of a horseshoe magnet.
Protecting the Earth from Harmful Radiations
Created by intense and dynamic magnetic forces inside the Earth, the magnetosphere protects the Earth’s surface from solar winds, atmosphere erosion, radiation from coronal mass ejections, and deep space cosmic radiation. Solar winds are charged particles emitted from the Sun. Coronal mass ejections are gigantic clouds of magnetised radiation and solar plasma. They are very dangerous to most living organisms. The Earth’s magnetic field created a special layer (magnetosphere) that filtrates such dangerous entities. A magnetosphere is a region of the Earth’s atmosphere that is directly controlled by the planet’s magnetic field.
In other words, the magnetosphere acts as a cosmic guard that filters out unwanted radiation and particles that are harmful to living things on the Earth. It traps most of the dangerous radiation in the Van Allen Belts region. This region is at a safe distance from the habitable zone of most living beings.
Maglev (magnetic levitation) is the current fastest train system on the planet. They are made using the fundamental principles of repulsion and attraction in magnetism. Maglev trains are floating (levitation) above the magnetic tracks due to the specially directed magnetic fields. Linear induction motors propel these machines. In both these cases, magnetic fields play an important role in the execution of fundamental technologies. Apart from maglev trains, magnetic levitation is used in contactless melting, magnetic bearings and for product display purposes.