Consider two concentric spherical metal shells of radii $r_{1}$ and $r_{2}$ $(r_{2} > r_{1})$. If the outer shell has a charge $q$ and the inner one is grounded, the charge on the inner shell is

$A$ hollow closed conductor of irregular shape is given some charge. Which of the following statements are correct?

Which of the following statements are correct?
$A$. Inside the conductor, the electrostatic field is zero.
$B$. Electric field at the surface of a charged conductor does not depend on its surface charge density.
$C$. The interior of a charged conductor can have no excess charge in the static situation.
$D$. At the surface of a charged conductor, the electrostatic field must be normal to the surface at every point.
$E$. The electrostatic potential is zero everywhere inside a charged conductor.
Choose the correct answer from the options given below:

Consider the shown system of two concentric thin metal shells. The inner shell has charge $Q$,while the outer shell is neutral. The potential difference between the shells is $V$. If the shells are joined by a metal wire,then the potential of the inner shell is

Given below are two statements $:$ one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A) :$ The outer body of an aircraft is made of metal which protects persons sitting inside from lightning strikes.
Reason $(R) :$ The electric field inside the cavity enclosed by a conductor is zero.
In the light of the above statements,choose the most appropriate answer from the options given below.

$A$ sphere '$1$' with radius $R$ has charge $q$. Sphere '$2$' with radius $3R$ is far from sphere '$1$' and is initially uncharged. If the two spheres are now connected with a thin conducting wire,then the ratio $\frac{\sigma_1}{\sigma_2}$ of the surface charge densities is