A capacitor is an element of an electrical circuit that allows the accumulation of electrical charges. As a rule, electrons are electric charges.
Capacitor charging process
A capacitor is capable of storing electrical energy by accumulating charged particles on its plates. Thus, an electric field of a certain strength arises inside the capacitor. Imagine a classical capacitor device containing two plane-parallel plates. An electrical potential is applied to each capacitor plate. The potentials of each capacitor plate have the opposite sign. In practice, such a case corresponds to connecting a capacitor to a galvanic cell.
Charged particles at the negative pole of the galvanic cell flow to one of the capacitor plates. Thus, the other plate is charged with the opposite sign. This creates an electric field inside the capacitor device. The charging process continues until the voltage between the plates becomes equal to the voltage of the galvanic cell.
Typically, a dielectric material is placed inside the capacitor, so that the total voltage between the plates of the capacitor is the sum of the external applied voltage and the internal voltage generated by the polar particles of the dielectric material.
Capacitor charge value
So, each of the capacitor plates is occupied by a certain number of charged particles. Since the plates are a metallic substance, only electrons can be free charge carriers. Consequently, only one of the plates accumulates charged particles in the form of electrons, and their excess is formed on the other, creating a certain positive charge.
Thus, the total charge of a capacitor can be defined as the total charge of all electrons of one of the plates. This value can be calculated by knowing the value of the capacitance of the capacitor. In this case, the amount of charge of the capacitor will be equal to the product of the capacitance and the voltage between the plates.
The capacitance of a capacitor is a constant value that depends only on its configuration, therefore the total charge of a capacitor will depend only on the magnitude of the voltage. However, there is a way to increase the charge of the capacitor in two ways at the same time, by reducing the distance between the plates.
In this way, you can achieve both an increase in the capacitance of the capacitor and an increase in the voltage across it. That is why they try to keep the distance between the plates as small as possible.
