Question

A dielectric with a positive charge of 13 C has 18.75X10 ^18 electrons added to it. What is the net charge of the dielectric in coulombs ?

Answer 1

charge of electron:

$e=-1.6\cdot10^{-19}$ C

net charge of the dielectric:

$Q=13-1.6\cdot10^{-19}\cdot 18.75\cdot10^{18}=13-3=10$ C