Which scientist represented the types of charges?

Find the change in mass of a body if it is given a $+2 \, C$ charge.

Who represented the quantization of electric charge first and on what basis?

Four metal conductors having different shapes:
$1.$ $A$ sphere
$2.$ Cylindrical
$3.$ Pear
$4.$ Lightning conductor
are mounted on insulating stands and charged. The one which is best suited to retain the charges for a longer time is:

What is called electrostatics?

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