Two identical charges, both labeled q1q1 in the diagram, are placed on the xx axis at (−a,0)(−a,0) and (+a,0)(+a,0). The electric field is observed at point PP, located on the yy axis at (0,+a)(0,+a). Charge q2q2 is added at the origin so that the net electric field at the observation point PP is zero.   If q1=q1=3.5 μC and a=a=4.4 m, what is the value of charge q2q2, in microcoulombs?

An electron is projected with an initial speed v0 = 1.70×106 m/s into the uniform field between the parallel plates in (Figure 1). Assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. The electron enters the field at a point midway between the plates. If the electron just misses the upper plate as it emerges from the field, find the magnitude of the electric field.         Express your answer in newtons per coulomb. Suppose that in the figure the electron is replaced by a proton with the same initial speed v0v0. Would the proton hit one of the plates? What would be the direction of proton's displacement?   displacement is upward displacement is downward

We have calculated the electric field due to a uniformly charged disk of radius R, along its axis. Note that the final result does not contain the integration variable r: R. Q/A 2€0 Edisk (x² +R*)* Edisk perpendicular to the center of the disk Uniform Q over area A (A=RR²) Show that at a perpendicular distance R from the center of a uniformly negatively charged disk of CA and is directed toward the disk: Q/A radius R, the electric field is 0.3- 2€0 4.4.1b

Why is C the answer?I need help figuring out this problem.