1. MAGNETISM Normally denoted by B
Magnetic forces affect moving charged particles*
Forces are perpendicular to both magnetic field and direction of motion
*Or objects made of charged particles
Magnetic Field B
velocity v
charge q
Force F

2. Magnetic units Magnetic field units: Ns/Cm Called a Tesla (T)
A Tesla is a big magnetic field
MRI magnet -> 1-4 Tesla

3. Electric Field Lines Graphical Illustration of Electrical Fields
Lines start on positive charges and end on negative
Number of lines from/to a charge is proportional to that charge
Density of lines tells strength of field. + - + -

4. Magnetic Field Lines Graphical Illustration of Magnetic Fields
Lines start on north pole and end on south pole
Opposite poles attract, like poles reply
Density of lines tells strength of field.
Key differences between magnetic fields and electric fields:
All magnets have a north and south pole! No such thing as an isolated north or south pole. (have magnetic dipoles, not monopoles)
Different force laws!

5. Vector Product Vector product -> two vectors make a vector
Geometric
C has magnitude ABsinq. Direction perpendicular
to the plane containing A and B.
Algebraic

6. The right hand rule
Force F
velocity v
Magnetic Field B

7. Magnetic Force Can only affect moving particles!
Force depends on charge just like electric fields
Force is maximum when the velocity and field are perpendicular, and zero when they are parallel
When the velocity and field are neither perpendicular nor parallel, the force still exists!

8. 3-d directions of vectors
into the plane
The two vectors shown represent the velocity and the magnetic field. For a negatively charged particle, which way will the particle accelerate?
A) C)
B) D)
velocity v
Magnetic Field B
out of the plane