Two charges are placed as shown in Fig. 21.53. The magnitude of q1 is 3.00 µC, but

Question:

Two charges are placed as shown in Fig. 21.53. The magnitude of q1 is 3.00 µC, but its sign and the value of the charge q2 are not known. The direction of the net electric field E at point P is entirely in the negative y- direction.
(a) Considering the different possible signs of q1 and q2, there are four possible diagrams that could represent the electric fields E1 and E2 produced by q1 and q2. Sketch the four possible electric field configurations.
(b) Using the sketches from part (a) and the direction of E, deduce the signs of q1 and 92.
(c) Determine the magnitude of E.