Electric field and potential : The graph in the figure shows the variation of the electric potential V(x) (in arbitrary units) as a function of the position x (also in arbitrary units). Which of the choices below correctly describes the orientation of the x-component of the electric field along the x-axis?

Question

Quizplus · Accepted Answer

The electric field is proportional to the negative gradient of the electric potential. From the graph, we can see that the slope of the graph is positive from x = -2 to x = 0, and negative from x = 0 to x = 2. Therefore, the x-component of the electric field is positive from x = -2 to x = 0, and negative from x = 0 to x = 2, resulting in choice B being the correct answer.

Electric Field and Potential : the Graph in the Figure