An attractive and repulsive phenomenon produced by a moving electric charge.
Ability of certain materials to attract iron, cobalt, or nickel.
Nature of Magnetism
Electrons possess a characteristic called “spin.”
Certain elements have electrons that “spin” in the same direction.
The collective motion of the charged atomic particles (the e-) results in a magnetic dipole & force field.
The magnetic force field produced is perpendicular to the plane of the motion of the e-.
Magnetic Fields (Lines of Force, Lines of Flux)
The force field that exists inside and outside a magnet.
Magnetic Field Strength
Stronger magnet has more lines 🡪 greater Flux Density (flux lines per square meter).
Measured as Tesla or Gauss.
Direction of Lines
North to South outside the magnet.
South to North inside the magnet.
Lines never intersect.
Classifications of Magnets
Natural
Earth
Lodestone
Artificial permanent
Alnico
Neodymium
Electromagnets
Temporary due to moving electric current
Laws of Magnetism
Repulsion-Attraction
Like poles repel; unlike poles attract
Inverse Square Law
Force between two magnetic fields directly proportional to product of their magnitudes and inversely proportional to the square of the distance between them.
Magnetic Poles
Every magnet has 2 poles
Magnetic Induction
Non-magnetized iron brought within a magnetic field; domains of iron line up in orderly fashion, iron is temporarily magnetized (magnetic induction)