Two concentric spherical shells of radius $R_1$ and $R_2$ have $q_1$ and $q_2$ charge respectively as shown in figure. How much charge will flow through key $k$ when it is closed
${q_2}\,\left( {\frac{{{R_1} + {R_2}}}{{{R_2}}}} \right)$
$\frac{{{q_1}{R_2} + {q_2}{R_1}}}{{{R_2}}}$
${q_2}\,\left( {\frac{{{R_2} - {R_1}}}{{{R_2}}}} \right)$
$\frac{{{q_1}{R_2} - {R_1}{q_2}}}{{{R_2}}}$
An empty thick conducting shell of inner radius $a$ and outer radius $b$ is shown in figure.If it is observed that the inner face of the shell carries a uniform charge density $-\sigma$ and the surface carries a uniform charge density $ '\sigma '$
If another point charge $q_B$ is also placed at a distance $c ( > b) $ the center of shell, then choose the correct statements
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 thin conducting shells of radii $R$ and $3R$ are shown in the figure. The outer shell carries a charge $+ Q$ and the inner shell is neutral. The inner shell is earthed with the help of a switch $S$.
A metallic rod is placed in a uniform electric field. Select the correct option.
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 $B$.