Week 1

Basic Facts

NOTE: Many of the facts in these early weeks are true ONLY for the case when the charges creating the electric field are at rest or very nearly so.

Coulomb's Law: The force F between two point charges Q1 and Q2 located at positions r1 and r2
respectively is given by
F = Q1 Q2 (r1 - r2)
       4πε₀ |r1 - r2|³
The force F on a particle with charge q is caused by an electric field E and is given by
F = q E

Principle of Superposition: The electric field at every point in space is the vector sum of the electric fields from each of the individual charges.

The electric field E measured at point r due to a point charge Q at position r' is given by

E = __Q_(r - r')
       4πε₀ |r - r'|³

The electric field in the interior of a conductor is zero.