In physics, a ferromagnetic material is said to have magnetocrystalline anisotropy if it takes more energy to magnetize it in certain directions than in others.

Magnetite is a mineral and one of the main iron ores.

Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is one aspect of the combined phenomenon of electromagnetism.

Magnetic susceptibility is a measure of how much a material will become magnetized in an applied magnetic field.

Magnetic particle Inspection (MPI) is a non-destructive testing (NDT) process for detecting surface and shallow subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys.

Magnetic energy and electrostatic potential energy are related by Maxwell's equations.

Magnetic confinement fusion is an approach to generate thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of a plasma.

A magnetic circuit is made up of one or more closed loop paths containing a magnetic flux.

Magnet wire or enameled wire is a copper or aluminium wire coated with a very thin layer of insulation. It is used in the construction of transformers, inductors, motors, generators and other applications that require tight coils of insulated wire.

A magnet is a material or object that produces a magnetic field.

Hot, thick, molten (liquid) rock found beneath the Earth's surface; formed mainly in the mantle.

Machine learning is the study of computer algorithms that improve automatically through experience and by the use of data.

A machine is a human-made device that uses power to apply forces and control movement to perform an action.

A maceral is a component, organic in origin, of coal or oil shale.

In photometry, luminous flux or luminous power is the measure of the perceived power of light.

A measure of how well a light source produces visible light.

Luminescence is spontaneous emission of light by a substance not resulting from heat; or "cold light".

A luminescent solar concentrator is a device for concentrating solar radiation in particular, to produce electricity.

The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total quantity of visible light emitted by a source per unit of time.

Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces.