Two charged conducting spheres of radii $a$ and $b$ are connected to each other by a conducting wire. The ratio of charges of the two spheres respectively is:

The dimensions of an atom are of the order of an $\mathring{A}$ $(10^{-10} \ m)$. Thus,there must be large electric fields between the protons and electrons. Why,then,is the electrostatic field inside a conductor zero?

$A$ spherical conductor of radius $2 \, m$ is charged to a potential of $120 \, V$. It is now placed inside another hollow spherical conductor of radius $6 \, m$. Calculate the potential to which the bigger sphere would be raised. (in $, V$)

Consider two conducting spheres of radii $R_1$ and $R_2$ with $(R_1 > R_2)$. If the two are at the same potential,the larger sphere has more charge than the smaller sphere. State whether the charge density of the smaller sphere is more or less than that of the larger one.

Two conducting spheres $A$ and $B$ have radii $1 \, mm$ and $2 \, mm$ respectively and are charged. They are placed at a distance of $5 \, cm$. When they are connected by a conducting wire,the ratio of the electric field intensities on their surfaces at equilibrium is:

Explain the construction of a Van de Graaff generator with a diagram and describe its uses.