Understanding Electric Fields with Field Lines and Equipotential Surfaces

1. Electric Field Lines:

   • The direction of these lines shows where a positive charge would move.
   • The number of lines close together tells us how strong the electric field is.
   • Lines go from positive charges to negative charges, like how they flow from a point charge.

2. Equipotential Surfaces:

   • These surfaces are always at a right angle to the field lines.
   • If you move along one of these surfaces, you don’t have to do any work; this means there’s no energy needed ($W = 0$).
   • The difference in electric energy between surfaces can be found using the equation: $V = k \frac{q}{r}$. Here, $k$ is about 9 billion ($9 \times 10^9$ N m²/C²).