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Charging a capacitor

As we know, the capacitor is a place where electrical charges (positive and negative) are stored. hence, we have to understand that a capacitor will undergoes the process of CHARGING and DISCHARGING. Once it stores the electrical chargers (and energy) , they need to be charged up and to release the stored energy for particular use, the capacitor is discharged.

CHARGING PROCESS

HOW A CAPACITOR IS CHARGED?
Figure 1: Charging the capacitor
When the switch is closed like in a figure above, when the circuit is on
  • the electrons will flow from negative terminal of the battery. 
  • they go to the nearest plate that is plate A.
  • At the same time, the original electrons at plate B will flow to the positive terminal of the battery, leaving positive charges at the this plate. 
  • This process are collecting electrons at plate A and positive charges at plate B. The flow of electrons stop when the potential,V between the plates (due to the existence of positive & negative charges) equal to the potential difference of the battery. 
** note that originally both plates are neutral - that does not mean it has no charges at all, BUT the number of positive and negative charges are equal. Hence, the plates are neutral.

The graph of charging a capacitor is shown below:

Figure 2: Graph of Charging process of capacitor


References: 
Image : https://www.howequipmentworks.com/defibrillator/collecting_electrons/
Image 2: https://a-levelphysicstutor.com/field-capacit-2.php
Book: 'Advance Physics for You', by Keith Johnson.et al.
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