Two metallic spheres of radii $1\,cm$ and $2\,cm$ are given charges ${10^{ - 2}}\,C$ and $5 \times {10^{ - 2}}\,C$ respectively. If they are connected by a conducting wire, the final charge on the smaller sphere is
$3 \times {10^{ - 2}}\,C$
$1 \times {10^{ - 2}}\,C$
$4 \times {10^{ - 2}}\,C$
$2 \times {10^{ - 2}}\,C$
Two charged conducting spheres of radii $a$ and $b$ are connected to each other by a wire. What is the ratio of electric fields at the surfaces of the two spheres? Use the result obtained to explain why charge density on the sharp and pointed ends of a conductor is higher than on its flatter portions.
Two spheres of radius $R$ and $2R$ having charge $Q$ and $2Q$ respectively are placed far away from each other. How much charge will flow when key $'k'$ is pressed ?
Assertion : A metallic shield in form of a hollow shell may be built to block an electric field.
Reason : In a hollow spherical shield, the electric field inside it is zero at every point.
Show that electrostatic potential is constant throughout the volume of the conductor and has the same value (as inside) on its surface.
A conducting sphere $A$ of radius $a$, with charge $Q$, is placed concentrically inside a conducting shell $B$ of radius $b$. $B$ is earthed. $C$ is the common centre of the $A$ and $B$.