Question

A solid metallic sphere is placed in a uniform electric field. Which of the curves shown in figure represent the lines of force correctly?

• A. $\left(a\right)$
• B. $\left(b\right)$
• C. $\left(c\right)$
• D. $\left(d\right)$

Answer 1

The correct option is D $\left(d\right)$

Consider a Gaussian surface inside the metallic sphere. The charge enclosed by the Gaussian surface is zero (since metallic sphere is a conductor and charge lies only on the surface). Therefore, electric flux is zero.
Now, Electric Flux = Electric Field * Area
but area cannot be zero. Therefore Electric field inside the sphere is zero.
If electric field had any component parallel to the surface of the conductor, then this would cause surface charges to move. Therefore the electric field must lie perpendicular to the surface everywhere.