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In physics, a dielectric is an insulating (or very poorly conducting) material. The material can be solid, liquid or gaseous. When a voltage difference is applied to top and bottom of a cylinder filled with a dielectric, no current will flow inside the cylinder because, unlike metals, a dielectric has no free-or loosely bound-electrons that can drift through the material. Instead, electric polarization occurs. The positive charges within the dielectric are displaced minutely in the direction of lower voltage, and the negative charges are displaced minutely in the opposite direction. When the molecules constituting the dielectric are polar (like water molecules), the molecules will align in the field, thus contributing to the electric polarization. Inside the cylinder no net charge density will arise because the charges in adjacent volume elements cancel. However, at the top and bottom of the cylinder an uncanceled surface charge will appear, and this surface charge (positive at the low voltage side and negative at the high voltage side) will oppose the electric field associated with the voltage difference. Thus, the polarization of the dielectric reduces the electric field inside the dielectric. Dielectric material is characterized by an intrinsic property called relative permittivity, usually denoted by εr (formerly this was known as the dielectric constant). The relative permittivity describes the ease of the polarization of the material and determines the size of the surface charge densities at the top and bottom of the cylinder. The Coulomb force between two permanent electric point charges placed inside a dielectric medium is 1/εr smaller than it would be in a vacuum due to the polarization of the dielectric medium by the point charges. The quantity of electric energy stored per unit volume of a dielectric medium is proportional to εr. The capacitance of a capacitor filled with a dielectric is a factor εr greater than it would be in vacuum. Reference: http://en.citizendium.org/wiki/Dielectric
Dielectric is a substance that can transport electricity without conducting it.
Wiki User
∙ 10y ago
Wiki User
∙ 9y agoA dielectric material is an electrical insulator that's able to be polarized by an electric current. A dielectric cell is, as such, a cell containing this material.
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For an insulating material dielectric strength and dielectric loss should be respectively?
For an insulating material dielectric strength and dielectric loss should be respectively
What happens when dielectric breakdown occurs?
The dielectric,usually the insulator between the plates of a capacitor, can be overstressed by the application of too high voltages applied to the capacitor plates. The dielectric breaks down and a current flows between the plates until,either they are discharged, or an equilibrium is reached,below the working voltage of the capacitor. If the dielectric is damaged in this process he capacitor must be replaced. Some dielectric material self heal and can recover from an over voltage.
What is the material use in the capacitor?
Capacitors are named after their dielectrics. So, an 'air capacitor' uses air as its dielectric, a 'mica capacitor' uses mica as its dielectric, and so on. There are lots of different dielectric used to separate the plates of a capacitor, each with different permittivities and dielectric strengths. As the perfect dielectric (i.e. one with both a very high permittivity and a very high dielectric strength) doesn't occur, the choice of dielectric is always a compromise between it permittivity and dielectric strength.
Is dielectric strength the same as dielectric constant?
No, these are two unrelated properties of a material.
Boundary conditions for perfect dielectric materials?
boundary conditions for perfect dielectric materials
For an insulating material dielectric strength and dielectric loss should be respectively?
For an insulating material dielectric strength and dielectric loss should be respectively
What is dielectric constant in chemical terms?
dielectric constant
For an insulating material dielectric strength and dielectric loss should be respectively high or low?
For an insulating material dielectric strength and dielectric loss should be respectively high or low
What is dielectric test in transformer?
why need dielectric test for transformer
What happens when dielectric breakdown occurs?
The dielectric,usually the insulator between the plates of a capacitor, can be overstressed by the application of too high voltages applied to the capacitor plates. The dielectric breaks down and a current flows between the plates until,either they are discharged, or an equilibrium is reached,below the working voltage of the capacitor. If the dielectric is damaged in this process he capacitor must be replaced. Some dielectric material self heal and can recover from an over voltage.
What is the material use in the capacitor?
Capacitors are named after their dielectrics. So, an 'air capacitor' uses air as its dielectric, a 'mica capacitor' uses mica as its dielectric, and so on. There are lots of different dielectric used to separate the plates of a capacitor, each with different permittivities and dielectric strengths. As the perfect dielectric (i.e. one with both a very high permittivity and a very high dielectric strength) doesn't occur, the choice of dielectric is always a compromise between it permittivity and dielectric strength.
What is the sodium hypochlorite dielectric constant?
dielectric constant for sodium Hypochlorite
What is thermal loss in dielectric heating?
Thermal loss in dielectric heating
What is leaky dielectric?
A leaky dielectric is a poorly conducting liquid. Refer to "ELECTROHYDRODYNAMICS: The Taylor-Melcher Leaky Dielectric Model" for more information.
For an insulating material dielectric strength and dielectric loss should be what?
high and high
Is dielectric strength the same as dielectric constant?
No, these are two unrelated properties of a material.
What is dielectric breakdown?
The dielectric breakdown strength is 3,000 volts per millimeter.
