Field lines and equipotentials
Posted in Physics, Charge and fieldField lines
Electric field lines always start and end on charges and travel from positive to negative:
Field lines are close together (more dense) in strong fields and further apart in weak fields. In the diagram below the field from B is stronger than that of A as demonstrated by the more tightly packed field lines:
When drawn, field lines must never cross each other
Equipotentials
Equipotential lines show lines of equal potential (i.e. voltage). They are always drawn perpendicular to the field lines and follow the surface of the conductor.
In uniform fields
In a uniform field the lines are equally spaced (purple lines):
Each line represents an equal 'chunk' of the total potential:
In non-uniform fields
In a non-uniform field each equipotential still represents an equal chunk of potential but due to non-uniformity the spacing is not constant (purple lines):
Like field lines, equipotentials cannot cross each other.