I was discussing with my friend about electric field lines and he said that:
given a test charge at rest at a point in the region of the electric field the charge will continue to move along the path of the field line passing through that point.
When asked for how reliable this statement was he couldn't say anything for or against it, stating that he hasn't thought much about it and will talk about it later.
But now this statement is bugging me a lot because I can easily see it being true in a uniform electric field, but can't say so in the case of a non-uniform one.
- So can someone tell me if a stationary charge allowed to move will follow the path of electric field lines or not?
One thing that I noticed is that if that were the case then both the force vector and velocity vector will point in the same direction.
Best Answer
No, charged particles do not need to move along the path of field lines. The field lines will just show the direction of acceleration, but just because acceleration is in some direction doesn't mean the particle moves in that direction. This is true for all motion, not just charged particles in electric fields.
Of course if the charge starts at rest in a uniform field then the charge will move with the field lines. However, in general even in a uniform field this will not be the case (As a simple example think about projectile motion).