What is a magnetic field?
A magnetic field describes the physical field around magnets, moving charges and changing electric fields.
How it works and key principles
Sources and effects: Moving electric charges generate magnetic fields. Such fields can exert forces on moving charges and magnets; a compass aligns with Earth’s field. Field lines are a visualization tool, not physical strings in space. Strength and direction vary with position.
Evidence, examples and limits
Applications: Changing magnetic flux induces voltage in generators, while motors use magnetic forces. Earth’s magnetic field interacts with the solar wind. Although magnetic fields and electromagnetic radiation are related, the static field of a magnet is not itself a radio wave.
Related topics
What is light?What is gravity?What is meiosis?What is entropy?EarthWhat is an isotope?What are the layers of the atmosphere?What is a polymer?What is a chemical reaction?What is evolution?What is sound?What is pressure?What is force?What is the scientific method?What is CRISPR?What is a galaxy?What is DNA?What is a stem cell?What is the ozone layer?What are meteors and meteorites?How does soil form?What is quantum physics?What is an ice age?What is a virus?What is a solar eclipse?What are acids, bases and pH?What is a fossil?What is a comet?MoonWhat is a lunar eclipse?What is an exoplanet?What is a neutrino?What is a microbiome?What is the cosmic microwave background?What is thermodynamics?What is relativity?What is chemical equilibrium?What is a chemical bond?What is the water cycle?What is an asteroid?What is ocean acidification?What is a star?What is the Standard Model of particle physics?What is the rock cycle?Solar systemWhat is a mitochondrion?What is plasma?What is gene expression?What is a nebula?What is the Big Bang?