For what type of charge distribution,electric field can be obtained by using Coulomb's law and superposition principle?

How can an object be charged by contact?

The number of electrons in $1.6 \, C$ charge will be

$A$ body can be negatively charged by

We have three identical metallic spheres $A, B$ and $C$. $A$ is given a charge $Q$,and $B$ and $C$ are uncharged. The following processes of touching of two spheres are carried out in succession. Each process is carried out with sufficient time.
$(i)$ $A$ and $B$
$(ii)$ $B$ and $C$
$(iii)$ $C$ and $A$
$(iv)$ $A$ and $B$
$(v)$ $B$ and $C$
The final charges on the spheres are

When $10^{14}$ electrons are removed from a neutral metal sphere,the charge on the sphere becomes ...... $\mu C$.