Question

Background pertinent to this problem is available in Interactive LearningWare 18.3. A uniform electric field exists everywhere in the x, y plane. This electric field has a magnitude of 5200 N/C and is directed in the positive x direction. A point charge -6.8 × 10-9 C is placed at the origin. Find the magnitude of the net electric field at (a) x = -0.16 m, (b) x = +0.16 m, and (c) y = +0.16 m.

Answer 1

(a) x = -0.16 m

E due to point charge is

As the point charge is negative, it will create field towards itself or along +x axis.

Therefore, net field is

(b) x = +0.16 m

As above, we will obtain E = 2390.62 N/C

But here point lies on + x-axis and charge will create field towards itself (towards origin), thus its field points now in -x direction. Therefore, net field is

(c) y = +0.16 m

As the distance is same and charge is same, E = 2390.62 N/C (along negative y axis)

E horizontal is 5200 N/C. Thus, net field is