22 Jun Grasp the science of magnetism from our physics tuition
Magnetism can be described as physical phenomena that come into action due to the force produced by magnets. Magnets are defined as objects that produced a magnetic field that is invisible but with notable effects like pulling ferromagnetic items such as iron fillings. Magnets are also able to attract or repel other magnets. Magnetism is a component of one of the strongest natural forces called electromagnetism. The magnetic field is due to the Lorentz force that exerts a force on the particles. Magnetic fields are measured in units that are defined as Tesla.
What causes magnetism?
According to a research by BBC, magnetism is caused by the motion of electrically charged particles. The movement of these particles will result in a field being set up. The electrically charged particle in a magnetic field is acted upon by a force and it depends on the magnitude of the charge, the velocity of the particle, and the strength of the magnetic field.
As already established, the cause of magnetism is the motion of electrically charged particles and this has further effects in magnetism. Due to the electrons’ angular momentum, their spins cancel each other since their magnetic fields are in opposite directions. However, there are atoms where some electrons are not paired and their spins are not cancelled. These un-cancelled spins are able to cause a directional magnetic field.
The direction of these spins is very important as it is a deciding factor in the direction of the magnetic field. If a number of un-cancelled spins are in the same direction, they will combine to form a directional magnetic field that can be picked up on a microscopic scale. Magnetic fields emerge from a source and these sources are bipolar, meaning they both have both North and South poles. Opposite poles tend to attract and similar poles repel each other.
There are materials that include iron and nickel which exhibit a characteristic described as ferromagnetism. This is useful to their prime use as rare earth magnets. This phenomenon is a result of unpaired electrons persistence without the application of an external magnetic field, also the lack of external current results in the formation of permanent magnets.
When a material is placed in a magnetic field, the material can temporarily gain magnetism and this phenomenon is referred to as paramagnetism. Paramagnetism happens when the magnetic field that the material is exposed to causes unpaired electrons in the material to have their spins align themselves and overwhelm the opposite force. The magnetic field is very weak and the effects are only noticeable in very cold temperatures.
This is a concept that has vast practical uses in modern-day science. Moving a wire into a magnetic field causes a current to be induced in the wire. The effects of moving an electric charge in motion will result in a magnetic field being produced. The movement of the wire determines the shape of the magnetic field. If the magnetic field moves straight at the straight wire (90 degrees), a magnetic field spiraling the wire is formed. If the wire is shaped into a loop, a magnetic field with a doughnut-like shape is formed. This is how electromagnets are formed. The strength of the electromagnet can be increased by placing a ferromagnetic core inside the coil.
Uses of magnetism
Magnets and the magnetism concepts are used to serve a variety of purposes. They play a major role in medicine as they are parts of essential medical equipment like MRI machines. They are also used in electricity generation processes as a major component of the power generators. Magnets are also important in electronics like speakers, televisions, and to make essential parts of computer hard drives.