Two charges are placed as shown in Fig. P21.96. The magnitude of q1 is 3.00 µC, but its...

Two charges are placed as shown in Fig. P21.96. 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 at point P is entirely in the negative y -direction. (a) Considering the different possible signs of q₁ and q₂, four possible diagrams could represent the electric fields produced by q₁ and q₂.

Sketch the four possible electric-field configurations. (b) Using the sketches from part (a) and the direction of , deduce the signs of q₁ and q₂. (c) Determine the magnitude of .