What electric field? The electric field in light? If you're talking about light, then the magnetic field is perpendicular but also tangent to the electric field (ie. it only touches the electric field at one point per cycle). The rigorous definition of tangent is only touching at one point. This is true for the magnetic field. Equipotential lines arent necessarily tangent to the E field. In light, this could also be an answer, depending on the specificity of your question. Anyhow, read a physics book and look up Maxwell's equations, it should be around there somewhere.
I thought equipotential lines by definition were tangent to electric field lines. After all, isn't the voltage function the negative gradient of the electric field function?
Hey hrtsurgeon, Is this question from the most recent mcat in august? I remember a question very similar, if not identical to that question in my physical sciences section. I put the answer that said something like "the direction of the electric field at that particular point" Im pretty sure this is right, because a tangent is like an instantaneous slope of a curve at any particular point, and if you have an electic field line, the tnagent at any point on that line would be the direction of the electirc field at that particular point.
This is the correct answer. It is definitely not the magnetic field because B lines run perpendicular to the E field lines.
