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naiasetvolo
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Why do we multiply permittivity of vacuum with relative permittivity?
What does this calculation mean?
What does this calculation mean?
Why is the vacuum permitivity used as a reference?nasu said:You do that in order to get the permitivity of the medium. That's all.
Rather than working with absolute values of permitivities it is preferred to use the vacuum permitivity as reference and tabulate the ratio of the permitivity of the medium to that of vacuum.
If vacuum is empty with no materiaparticle then why can we not just use the relative permittivity as a reference? If there is only emptyness why can we not dismiss vaacum and only focus on relative permittivity?nasu said:Good question. What would you choose as reference?
I am going out of my main question but if it is only "emptyness" then how can talk about as if it exists?naiasetvolo said:If vacuum is empty with no materiaparticle then why can we not just use the relative permittivity as a reference? If there is only emptyness why can we not dismiss vaacum and only focus on relative permittivity?
But then if there are no materia particle in vacuum how can pressure exist and be less than atmospheric pressure? It makes it seem as we can not dissmiss vacuum and from that it gives me second thoughts on what I just said about dissmissing vacuum and only use relative permittivity. I am not sure nasu..
When I looked up vacuum, the source told me that there is not materia particle, then how does an electric force exist if there is no materia particle?nasu said:There is an electric force between charged particles in vacuum. So you cannot just dismiss it.
When you put the same particles in a medium, the force is reduced by a factor. That factor is the relative permitivity of the medium.
This is one reason to choose vacuum as reference. The force is largest in vacuum.
The rest is not physics but sort of philosophy. What means to "exist" and things like this. Really not interested in discussing these.
Because that's how I thought myself through it, that the existence of materia is by particle, therefore if particles exist that's somehow materia. Thank you, I have understood now.nasu said:Why do you think you need "materia" particles to have electric forces? Of course you have two charged particles, at least. But there is nothing else between or around them. This is what is meant by electric force in vacuum.
The permittivity of vacuum (represented by the symbol ε0) is a fundamental constant in physics that describes the ability of a vacuum to store electric charge. However, in most materials, the permittivity is not equal to ε0. Instead, it is multiplied by a factor known as the relative permittivity (εr) to account for the material's ability to store electric charge. This is necessary because the presence of other materials affects the strength of an electric field, and therefore, the amount of charge that can be stored in a given space.
The relative permittivity, also known as the dielectric constant, tells us about a material's ability to store electric charge. A higher relative permittivity means that the material can store more electric charge and therefore can withstand a stronger electric field before breaking down. In other words, it measures the resistance of a material to the formation of an electric field.
The relative permittivity of a material can be determined experimentally by measuring its capacitance (the ability to store electric charge) and comparing it to the capacitance of a vacuum. It can also be calculated by dividing the permittivity of the material by the permittivity of vacuum (εr = ε/ε0).
The relative permittivity is a dimensionless quantity, meaning it has no units. This is because it is a ratio of two quantities with the same units (permittivity of the material and permittivity of vacuum), which cancel each other out.
The permittivity of vacuum is used as a reference point because it is a universal constant that does not change with the presence of other materials. This allows for a standardized comparison between the permittivity of different materials, making it easier to understand and analyze their electric properties.