Dielectric Material Inserted Between Two Plates

Before going into the Dielectric Material Inserted Between Two Plates, Firstly, we have to know Dielectric or Dielectric Material.

A Dielectric is an electrical insulator. With the help of an applied electric field, the dielectric material can be polarized. When we place a dielectric material into an electric field, then through the material, the electric charges do not flow as a charge usually flows in an electric conductor. They don’t have free electrons that may drift through the material. Still, they shift slightly only from their average equilibrium, causing dielectric polarization.

In the direction of the field, the positive charges get displaced, and in the direction opposite to the field, the negative charges get shifted only because of the dielectric polarization.

A Short Note On Dielectric Material Inserted Between Two Plates

When we do not have any dielectric material between two plates of a capacitor, then air acts as a dielectric, allowing the capacitor to store a certain amount of energy and charge.

But, whenever we need and want to increase the amount of the charge and the energy, the capacitor stores and supplies the energy; we place the dielectric material between the two plates. While doing this, it makes the process of jumping harder for the electrons through those two plates. This process enables the capacitor to store a considerable amount of energy and charge without having the dielectric material. Inserting the dielectric material between the two parallel plates increases the overall capacitance of the whole system because the capacity of charge of storage increases with the help of dielectric material.

When we insert the dielectric material between the two plates, then due to charge polarization occurring on the dielectric’s either side, it starts producing the electric field around its area by itself attaching with those two plates, which acts in the opposite direction of the field, due to the source. 

With this, the net electric flux gets zero. This can affect the results in the capacitance.

Multiple Parallel Plate Capacitor 

A Multiple Parallel Plate Capacitor has multiple plates, and it contains various charge-carrying conductive materials plates, separated by a dielectric. The dielectric stops the plates from shorting out with each other. Leads connect from the outermost and last plates to a voltage source, allowing the discharging and charging of the capacitor. A typical capacitor claims a multiple plate effect into a cylinder by rolling two numbers of plates.

The multiple plate capacitor has an expression for it :

    C=Actual permittivity×(n-1)×A/d.

Where n=number of plates, 

           A=area of the cross-section of the         

               plates,

           d=distance of separation between 

               the plates.

Charge On Parallel Plate 

The two plates of the two parallel plates’ capacitor are equal measures and dimensions. They connect to the power supply. The plates that connect to the positive terminal acquire a positive charge. On the other side, the plates that connect to the battery’s negative terminal acquire a negative charge. 

Let’s suppose that a capacitor has electric charge Q and capacitance C, which is neutral electrically.                   

 U = Q²/2C = ½ QV               

Where,

The V is the potential difference between the plates. 

If the charge is different between the two plates of a parallel plate capacitor, then V1 will be the potential difference of plate 1, and Q1 will be the charge.

While the V2 will be the potential difference for the plate 2, the charge will be Q2 = −Q + δQ 

 U = 1/2Q1V1 + 1/Q2V2

             = ½ Q(V1-V2) + 1/2δV2

             U = Q²/2C + δQ²/ 2C20

The Principle Of Capacitor 

 Principle of the capacitor, A capacitor usually works on the principle so that the capacitance of a conductor increases considerably whenever the earthed conductor is brought near to itself.

Parallel Plate Capacitor: Suppose a parallel plate capacitor has two numbers of plane metallic plates. The first is A, and another one is B. They are placed parallel to each other. The plates will carry the charge as opposite and equally -Q and +Q.

Generally, the electric field between those plates due to the charges -Q and +Q will remain uniform, but the electric field lines at the edges.  

O = Q/A 

The electric field strengthens the plates.

E = O/KEo, where the Eo is equal to the permittivity of free space……(I)

The potential difference between the plates will be Vab = Ed = od/KEo……(ii)

Putting the value of o we will get, 

Vab =(Q/A)d/KEo = Qd/ KEoA 

Therefore, the capacitance of the capacitor,

C = Q/Vab = Q/(Qd/KEoA)

C = KEoA/d 

Conclusion

We now know what is Dielectric and what happens when Dielectric Material is inserted between two plates. By putting and inserting the dielectric material between the two plates, the capacitor stores a more significant amount of energy or charge than without having the dielectric material or dielectric slab between the two numbers of plates or multiple numbers of plates.

We also learned about the Multiple Parallel Plate Capacitor, the Charge On Parallel Plate, and the Capacitor Principle.