Week 2 Flashcards
Electrical charge of electron
-e
Electrical charge of proton
e
Coulomb’s Law
Coulomb’s law in Gaussian units
Direction of F
If Q and q are same charge, F points in the same direction as s, else it points in the opposite direction
Electric field of the source charges
Colombo’s law for an electric field
Denote the charge per unit volume
Electric field for charge distributions
dv’ instead of dv as it is an infinitesimal volume about r’
Use Dirac delta to construct charge density for a discrete charge q_1 at position r_1’
Rules for field lines
- continuous curves whose tangents at any point r are parallel to E(r)
- all lines must begin at pos charge/inf and end on neg charge/inf
- # of lines from a point source is proportional to the charge source and symmetrically distributed around it
Gauss’s Law on a closed surface
Where Q_s is total charge contained within surface S
Gauss’s law tells us
The flux through any closed surface, no matter its shape, is proportional to the sum of the charges enclosed within the surface.
It doesn’t matter where the source charges are located within
