A2L Item 210

Goal: Relate representations

Source: 283-342 Graph Ex(x)

We have a charge configuration
(shown at the right). Which graph is the plot of E_x(x), the
x component of the electric field, as you move along the
x-axis?

Commentary:

Answer

(6) Students should recognize that the field goes singular at the
charges. The only graphs doing that, #1 and #4, are eliminated because
the x-component of the field must be negative everywhere between the two
charges. Have students sketch the graph.