# relative permittivity

Discussion in 'Physics' started by bhuvanesh, Apr 12, 2014.

1. ### bhuvanesh Thread Starter Member

Aug 10, 2013
268
2
what is the effect of relative permittivity in respect to current.air has low and water has high relative permitivity.how does it affect the electric field.

Last edited: Apr 12, 2014
2. ### daviddeakin Active Member

Aug 6, 2009
207
27
Materials with higher permittivity can "hold" a higher density of electric flux for a given electric field strength. Or, looking at it the other way, for a given flux, the electric field strength will decrease as permittivity increases (putting it crudey, you need less voltage to make a given amount of flux 'flow' in the material*)

Remember the formula for capacitance:
C=εA/d
More permittivity (ε) means more capacitance, which means it holds more charge for a given voltage. More charge means more flux.

*flux does not actually "flow" anywhere; it simply exists in a given volume. But it can be tricky to talk abut it in everyday language without using the word "flow"!

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3. ### Roca New Member

Apr 18, 2014
3
0
I have read to that it may also be related to the intensity of a electric flux. (Just as permeability for magnetic flux). As daviddeakin explained, the capacitance formula is a good example to easily see that.