Magnetism - The force of attraction or repulsion between like and unlike…
Magnetism - The force of attraction or repulsion between like and unlike poles
Repel or Attract?
Likes poles repel.
Unlike poles attract.
Magnetic Force on a single charged particle
F = I x B x L x sin (theta)
The force (F) on a conductor of length (L) and current (I) in a B-Field (B)
F is force in Newtons, Q is charge in coulombs, v is velocity in m/s, and B is magnetic field in Tesla
I Gauss 10^-4 Tesla
F = B x Q x V
Force is greatest when path is perpendicular to the field.
Magnetic Field: region around magnet where magnetic forces act (has magnitude and direction).
Magnetic Field is proportional to current
Atoms of a magnet contain electrons that are in constant motion around atomic nuclei. This moving charge makes a tiny current and the electric charge.
Stronger fields are shown by closer lines.
Direction is defined by the direction of the north pole of a compass at that position.
Every spinning electron is a tiny magnet.
Magnetic fields of a pair of electrons cancel out.
Magnetic Domains: groups of atoms with aligned magnetic poles.
Magnetized: magnetic domains are arranged in the same direction.
Unmagnatized: magnet domains are randomly arranged.
Items can be demagnetized by excessive heating, passing electricity, and hammering.
Right Hand Rule
X's represent a magnetic field directed into the page, and dots represent a magnetic field directed out of the page.
Fingers - Magnetic Field (B)
Palm of Hand - Force (F)
Thumb - Current (I)
This can be used to find the direction of force.
Types of Magnets
Temporary Magnets: retain magnetic
properties for short amounts of time; examples include paper clips and nails rubbed against a magnet
When current is passed through loops of coiled wire, a strong temporary magnet called an electromagnet is formed.
Permanent Magnets: retain their
magnetic properties for a long time;
examples include iron, cobalt, and nickel