Three concentric conducting spherical shells have radius $ r, 2r$ and $3r$ and $Q_1, Q_2$ and $Q_3$ are final charges respectively. Innermost and outermost shells are already earthed as shown in figure. Choose the wrong statement.
$Q_1 + Q_3 = - Q_2$
$Q_1 = $ $\frac{-Q_2}{4}$
$\frac{Q_3}{Q_1}$ $= 3$
$\frac{Q_3}{Q_2}=\frac{-1}{3}$
A metallic rod is placed in a uniform electric field. Select the correct option.
$A$ and $B$ are concentric conducting spherical shells. $A$ is given a positive charge while $B$ is earthed. Then :-
Two conducting spheres of radii $5\, cm$ and $10\, cm$ are given a charge of $15\,\mu C$ each. After the two spheres are joined by a conducting wire, the charge on the smaller sphere is.......$\mu C$
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 the outer surface of the shell is earthed, then identify the correct statement(s)
Two concentric hollow conducting spheres of radius $r$ and $R$ are shown. The charge on outer shell is $Q$. What charge should be given to inner sphere so that the potential at any point $P$ outside the outer sphere is zero?