Inside a charged hollow sphere,at any point the electric field $(E)$ and potential $(V)$ are

Assertion : In a cavity within a conductor,the electric field is zero.
Reason : Charges in a conductor reside only at its surface.

$12 \mu C$ and $6 \mu C$ charges are given to two conducting plates having the same cross-sectional area and placed face to face close to each other as shown in the figure. The resulting charge distribution in $\mu C$ on surfaces $A, B, C$ and $D$ are respectively,

$A$ point charge is kept at the centre of a metallic insulated spherical shell. Then:

Three identical uncharged metal spheres are at the vertices of an equilateral triangle. One at a time,a small sphere is connected by a conducting wire with a large metal sphere that is charged. The center of the large sphere is on the straight line perpendicular to the plane of the equilateral triangle and passing through its center (see figure). As a result,the first small sphere acquires charge $q_1$ and the second acquires charge $q_2$ $(q_2 < q_1)$. The charge that the third sphere $q_3$ will acquire is (Assume $l >> R$,$l >> r$,$d >> R$,$d >> r$):

$A$ charge $+q$ is placed somewhere inside the cavity of a thick conducting spherical shell of inner radius $R_1$ and outer radius $R_2$. $A$ charge $+Q$ is placed at a distance $r > R_2$ from the centre of the shell. Then the electric field in the hollow cavity