Question

A solid non-conducting sphere of radius r = 20 cm carries a total charge of 2 nc spread uniformly within the volume of the sphere. Which of the following statements are correct?

1) The electric field inside the sphere is zero.
2) The electric field outside the sphere is zero.
3) The electric potential inside the sphere is zero.
4) The electric potential outside the sphere is zero.

Answer 1

The electric field inside the sphere is not zero, but constant and directed radially towards the center. The electric field outside the sphere is not zero, but decreases as 1/r^2. The electric potential inside the sphere is not zero, but constant and decreasing as you move towards the center. The electric potential outside the sphere is zero.

Step-by-step explanation:

To determine the correctness of the given statements, let's consider each option:

1. The electric field inside the sphere is zero. This statement is incorrect. Inside a non-conducting sphere with a uniformly distributed charge, the electric field is not zero. However, it is constant and directed radially towards the center of the sphere.
2. The electric field outside the sphere is zero. This statement is also incorrect. The electric field outside the sphere is not zero, but it decreases as 1/r^2, where r is the distance from the center of the sphere.
3. The electric potential inside the sphere is zero. This statement is incorrect. Inside a uniformly charged sphere, the electric potential is not zero. However, it is constant and decreasing as you move towards the center of the sphere.
4. The electric potential outside the sphere is zero. This statement is correct. Outside a uniformly charged sphere, the electric potential is zero. The potential only depends on the charge and the distance from the center of the sphere.

Therefore, statements 1) and 3) are incorrect, while statements 2) and 4) are correct.