In the above diagram, a charged particle is moving in an electric field, where the dotted red lines are equipotential lines. The charged particle is initially entered with a speed of \(v\) from the left of point A
. Then it passes points A
, finally arriving at point C
. It stops for a moment there at point C
, and then starts to move back to point A
. Which of the following statements is correct?
a) The charged particle is negatively charged.
b) The magnitude of the kinetic energy when the charged particle passes point B is half the kinetic energy when the charged particle passes point A.
c) The force acting on the charged particle at point C is not zero.