Magnetic fields are areas where magnetic forces can be measured. They are created by moving electrically charged particles, and they exert a force on other charged particles in the presence of a magnetic field. The strength of the magnetic field is determined by the amount of charge in the moving particle and the speed at which it is moving.
The most common type of magnetic field is called an electromagnet, which is created when an electric current flows through a conductor such as a wire. The direction of the magnetic field produced by an electromagnet can be changed by changing the direction of flow of electric current through the conductor. Electromagnets are used in many devices, including motors, generators, relays, and solenoids.
The Earth’s magnetism is caused by currents flowing in its molten outer core. This generates a global dipolar magnetic field with north and south poles roughly aligned with the geographic north and south poles. The Earth’s magnetic field protects us from harmful cosmic radiation and solar wind; without it, life on Earth would not be possible.
Magnetic resonance imaging (MRI) uses strong magnetic fields to produce detailed images of organs and tissues inside the body. MRI machines are found in hospitals and clinics around the world and have revolutionized diagnostic medicine.
Magnetic fields are invisible lines of force that surround magnets and electric currents. They exert a force on objects that contain either iron or electric charges moving through them. The strength of this force depends on three factors: the strength of the magnet or current, distance from it, and angle between them (if applicable). All magnets have north-seeking poles (N) and south-seeking poles (S). Opposite poles are attracted to each other while like poles repel each other—this forms the basis for how motors work using electricity and magnets together!