?

SAT® Subject Test in Physics

Free Version

Upgrade subject to access all content

Difficult

Two Charge Zero Electric Field

SATPHY-KQXNE9

In which pictured region (if any) in the diagram below could the electric field possibly be zero (excluding points at infinite distance from the spheres)?

The diagram shows two spheres, charged uniformly as indicated. All regions are along a line connecting the centers of the objects.

Region $A$ is anywhere to the left of the positive charge. Region $B$ is to the right of the positive charge and closer to the positive charge than to the negative charge. Region $C$ is to the right of the positive charge but closer to the negative charge than to the positive charge. Region $D$ is anywhere to the right of the negative charge.

A

$A$

B

$B$

C

$C$

D

$D$

E

There is no region where the electric field could possibly be zero.