9702 · 18.2
Uniform electric fields — FAQ
Frequently asked questions for 9702 Uniform electric fields. Direct answers first, then deeper explanation — then practise with marking.
How do uniform electric fields differ from radial electric fields?
Uniform fields have constant strength and direction, represented by parallel lines. Radial fields (from point charges) have strength that decreases with distance and lines that spread out from a central point.
Why does a charged particle follow a parabolic path in a uniform electric field?
When a particle enters perpendicular to the field, it experiences a constant electric force (and thus constant acceleration) in one direction, while maintaining constant velocity in the perpendicular direction. This combination of motions results in a parabolic trajectory, analogous to projectile motion under constant gravity.
What is the significance of equipotential lines being perpendicular to electric field lines?
This perpendicularity means that no component of the electric force acts along the equipotential line. Therefore, no work is done by the electric field when a charge moves along such a line, consistent with the definition of equal potential.