Question

A solid conducting sphere has a positive charge. A nearby electron experiences a force due to the electric field produced by the solid conducting sphere. What direction is this force?

• A. Toward the sphere
• B. In a circular path perpendicular to the E-field
• C. Away from the sphere
• D. The direction of the force cannot be determined without also knowing the direction of the velocity of the electron.

Answer 1

The correct option is A Toward the sphere

The electric field outside the conducting sphere is radially outward the sphere because ${\overrightarrow{E}}_{out}=\frac{kQ}{r^2}\hat{r}$

Thus, the force on electron $(-e)$ due to the field $E_{out}$ is $\overrightarrow{F}=(-e){\overrightarrow{E}}_{out}$ . Hence it indicates the force will be toward the sphere.