The Magnetic Fields

A negative charge generates an electric field.
A moving charge generates a magnetic field.

What do we mean by permanent magnet and how it is generated?

The magnet is a magnetic field that is caused by the individual electrons in the last orbit of some atoms.
 

The Electron orbits

1. About the atomic nucleus.
2. About itself (called a spinning motion). This rotation generates a very small magnetic field.

Atoms with even number of electrons in their last orbit do not generate a magnetic field because:

 (Electrons in each state rotate opposite to each other, so they cancel each other out)

Magnet types

1. Permanent magnet is Fe3O4.
2. Temporary magnets are Materials that are magnetized under the influence of another magnetic field and for a specified period of time (magnetization goes away with the removal of the affecting field).

3. A magnet generated by an electrical current.

 

The Magnetic Force "FB": (assuming there is no electric field)

Angle " θ " Cases:

The Case	What does it mean?
if θ = 0 àsin 0 = 0 àFB = 0	The charge is moving parallel or opposite to the direction of "B"
if θ = 90 à sin 90 = 1 à FB = qvB	FB is perpendicular to the plane containing the magnetic field "B" and charge velocity "v"
θ May be any value other than 0 or 90

FB direction varies according to charge type: (when θ = 90 ) 

If the charge is negative (electron) à the FB is negative and its direction is downward	If the charge is positive (proton) à the FB is positive and its direction is upward
Upside-Down Left Hand Rule	Left Hand Rule

The magnetic field "B":

We can infer the law of the magnetic field "B" from the law of magnetic force "FB"

The unit of measurement for the magnetic field "B":