Question

Why one can ignore quantization of electric charge while dealing with microscopic that is large scale charges?

Answer 1

At the macroscopic level one deals with charges that are enormous compared to the magnitude of charge e . Since e = 1.6 × 10^-19 C , a charge of magnitude , say 1μC contains something like 10^13 times the electronic charge . At this scale , the fact that the charge can increase or decrease only in units of e is not very different from saying that charge can take continuous value . Thus at the macroscopic level , the  quantisation has no practical consequence and can be ignored .