Physics Quicksheets - Magnetism

Magnetic Fields are created by permanent magnets and moving charges.

*magnetic field lines depict the direction a compass needle would point if placed in the field from the North Pole to the South Pole

SI units = Tesla (T) = N*s/m*C

1 T = 10⁴ gauss

materials made of atoms with no unpaired electrons and that have no net magnetic field.

*weakly antimagnetic

materials have unpaired electrons and have a net magnetic dipole, but the atoms in these materials are usually randomly oriented so that the material itself creates no magnetic field.

*weakly magnetized in the presence of an external magnetic field.

materials have unpaired electrons and permanent atomic magnetic dipoles that are normally oriented randomly so that the material has no net magnetic dipole.

*will become strongly magnetized when exposed to a magnetic field or under certain temperatures.

• *Curie Temperature:
•                  above = paramagnetic
•                  below = permanently magnetized

• q = charge (+/-)
• v = velocity
• B = Magnetic Field

*the magnetic force is zero when a charge moves parallel or antiparallel to the magnetic field

*@ sin(90⁰): F = qvB = mv

*Note that the right-hand Rule gives the direction of magnetic force exerted on a proton. 

The direction of force on an electron is simply the opposite direction of the force on a proton.

F = iLBsinθ

x --> represents B fields pointing into the page.

* --> represents B fields pointing out of the page.

*right thumb points in the direction of current flow.

*Wrap your fingers around the wire as if you were grabbing it with your palm

*The direction that the fingers curl is the direction of the magnetic field.

*Waves can also be shifted with respect to one another by other fractions of a cycle, such as λ or 90^o out of phase.