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

While doing his experiment,Millikan one day observed the following charges on a single drop:
$(i)$ $6.563 \times 10^{-19} \ C$
$(ii)$ $8.204 \times 10^{-19} \ C$
$(iii)$ $11.50 \times 10^{-19} \ C$
$(iv)$ $13.13 \times 10^{-19} \ C$
$(v)$ $16.48 \times 10^{-19} \ C$
$(vi)$ $18.09 \times 10^{-19} \ C$
From this data,the value of the elementary charge $(e)$ was found to be:

$A$ positively charged glass rod is brought near an uncharged metal sphere,which is mounted on an insulated stand. If the glass rod is removed,what is the net charge on the metal sphere?

In Millikan's oil drop experiment for the determination of the charge on the electron,the reason for using oil is:

Write the definition of the unit Coulomb.

Select the correct statement about electric charge.