PH 122 Lecture Notes - Electric Field, Field Line, Electric Potential
Document Summary
Topo maps have lines of constant gravitational potential (that is, equal height) drawn on them. Topographical lines on a map are lines of constant elevation. These lines of constant height are thus lines of constant gravitational potential. We can also make a gravitational analogy with the electric field. The downhill force is greatest where the contour lines are closest together, and the direction of the force is perpendicular to the contours. The force felt by charges can be described by having the charges immersed inside electric fields. The electric field can refer to the force per unit charge (newtons per coulomb), or to a change in voltage over some change in distance (volts per meter). Volts, of course, are a unit of electric potential, and represent the electric energy per unit charge. Field lines can only begin and end on charges. Conductors are equipotentials; thus, field lines are perpendicular to conductors.
