Electric Field Lines: Does Positive Test Charge Follow?

[Mausam]

Does a positive test charge follows along the path of electric field lines if it is free to do so? I mean the trajectory of the charge is along the electric field lines and the field lines are not necessarily straight.

 

[robphy]

Does a positive test charge follows along the path of electric field lines if it is free to do so? I mean the trajectory of the charge is along the electric field lines and the field lines are not necessarily straight.

No. The positive test charge feels a force due to the field vector at that point. The charge's position gets updated and then feels another force at the new point, and so on.

Example... given a parallel plate capacitor, the field lines between the plates are perpendicular to the plates and the field strength is constant.
If a charged particle between the plates has a velocity initially parallel to the plate, that particle will follow a parabolic path.