Question

A glass rod was rubbed with silk and was found to have +5$\mu$C of charge. How many electrons got transferred and from which material?

Answer 1

$1.6\times {10}^{-19}C$ charge is contained in an electron.

Using conventional method
$\therefore$ 1 C charge is contained in $\frac{1}{1.6\times {10}^{-19}}$ electrons.
$\therefore$ $5\mu C$ charge is contained in $\frac{5\times {10}^{-6}}{1.6\times {10}^{-19}}$ electrons.

Also using the quantization of charge's logic :

$Q=\pm ne$

$n=\frac{Q}{e}=\frac{(5\times {10}^{-6})}{1.6\times {10}^{-19}}=3.125\times {10}^{13}\cong 3\times {10}^{13}$