Question

If dielectric constant and dielectric strength be denoted by $K$ and $X$ respectively, then a material suitable for use as a dielectric in a capacitor must have:

Answer 1

Hint:In order to answer the above question, we will discuss the terms dielectric constant and dielectric strength and try to understand them. We will also discuss the use of dielectric materials inside a capacitor to increase its capacitance. Finally, we will conclude our answer using all the information regarding the relation between the dielectric material and a capacitor.

Complete step by step answer:
As we know that a dielectric material is a non-metallic material that has a high specific resistance, a negative temperature coefficient of resistance, and a high insulation resistance.Dielectric material may also be described as a non-conducting material that stores electrical charges.

When an electric field is applied to a dielectric, the electric charges do not flow through the material; instead, they shift slightly from their average equilibrium positions, resulting in dielectric polarization. Positive charges flow in the direction of the field, while negative charges shift in the opposite direction of the field due to dielectric polarisation. This phenomenon produces an internal electric field inside the dielectric material, which decreases the total electric field.

A substance's dielectric constant is defined as follows: The ratio of the substance's permittivity to the free space's permittivity. It describes the amount of electric flux that a material can hold. It can be expressed as:
$K=\dfrac{\varepsilon }{{{\varepsilon }_{0}}}$
Where $K$ is the dielectric constant, $\varepsilon $ is the permittivity in medium and ${{\varepsilon }_{0}}$ is the permittivity in vacuum.

The ability of an insulating material to act as an insulator is known as dielectric strength. The maximum electric field that an insulating material can withstand before dielectric breakdown and being electrically conductive is known as its dielectric strength. The maximum voltage required to cause a dielectric breakdown in an electrically insulating material is also known as dielectric strength.

From all the above information, we can conclude that dielectric strength and dielectric constant are important parameters to consider when describing a capacitor. An electronic device called a capacitor is used to store electric charge. A dielectric insulating plate is sandwiched between the metal conducting plates in most cases.

The dielectric property of a capacitor is essential to its operation. The capacitor's ability to store charge is determined by the dielectric material sheet. It's critical to choose the right dielectric material.By increasing the dielectric constant and decreasing the separation between the parallel conducting plates, the capacitance value can be maximised. For this purpose, the strength of the dielectric medium also needs to be very good.

Therefore, the material which is suitable to be used as a dielectric inside a capacitor should have large dielectric constant $K$and also should have a very high dielectric strength $X$ to withstand the electric field.

Note: It is very important to note that the capacitor is a device used to store energy in the form of an electric field. A simple capacitor is made up of two conducting parallel plates separated by a certain distance. The gap between the capacitor can also be a vacuum. But the dielectric material is used between the plates as they help in increasing the charge that is stored on the capacitor plates.