Between two parallel charged plates the field is uniform: evenly spaced, parallel field lines, with strength E = V / d. A charged particle fired across such a field follows a parabola, exactly as a projectile does in gravity. Change the voltage and separation and launch the charge.
MissionPredict how the field strength changes when the plate separation doubles.Streak 0Best 0
Keeping the voltage fixed, doubling the plate separation d changes the field strength E to:
field strength E = V / d15000 V m⁻¹
deflection toward negative plate—
The field is the same everywhere between the plates. A positive charge accelerates toward the negative plate, tracing a parabola while its horizontal speed stays constant.