Question

Two metallic spheres have same radii. On of them is solid and the other is hollow. They are charged to the same potential. The charge on the former is $q_1$ and that of the latter is $q_2$. We have

• A. $q_1=q_2$
• B. electrostatic field inside both of them to be zero.
• C. electrostatic potential in both the sphere at an inside point same as that at the surface.
• D. Charge in both is effectively assumed to be concentrated at the centre of field strength at an external point.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A $q_1=q_2$
B electrostatic field inside both of them to be zero.
C electrostatic potential in both the sphere at an inside point same as that at the surface.
D Charge in both is effectively assumed to be concentrated at the centre of field strength at an external point.

Since radii are same, so charge will be the same. The electrostatic field inside both of them, i.e. the hollow and the solid conducting spheres will be zero. The electrostatic potential in both of them at an inside point will be the same as that the surface. The charge in both may be considered to be effectively concentrated at the respective centres for calculating the electrostatic field strength at an external point.