Hey guys, I was hoping someone could clear up what seems to me to be an apparent contradiction in my course notes, let me explain:
From the very beginning of our notes on electromagnetic fields and waves, the electric flux intensity vector E is defined to be the force a charge q would experience when in the presence of this field such that E is equal to kq1/r^2 where k is a constant which is dependent on the medium that the field is in and r is the distance between q and q1. It was found that the total flux of E ψE is equal to 4∏kq. A new term ε (permittivity) is defined to be 1/(4∏k) such that the electric flux density vector D is equal to εE. This means that the total flux of D ψD is q.
From the above, my understanding was that the D field was independent of the medium through which is travelled. My notes then go on to describe "the distribution of flux through non uniform media" which uses as example of two large blocks of different permittivities ε1 and ε2. In this example, the problem that I have with it is that the the E field in medium 1 - E1 is equated to E2 in medium 2 such that E1 = E2 = E. All further derivations in this section stem from this. From what I have mentioned above, I dont see how it is possible for E1 to have the same intensity as E2 if the media have different permittivites? I would have thought that a good starting point would have been to equate the D vectors instead.
From the very beginning of our notes on electromagnetic fields and waves, the electric flux intensity vector E is defined to be the force a charge q would experience when in the presence of this field such that E is equal to kq1/r^2 where k is a constant which is dependent on the medium that the field is in and r is the distance between q and q1. It was found that the total flux of E ψE is equal to 4∏kq. A new term ε (permittivity) is defined to be 1/(4∏k) such that the electric flux density vector D is equal to εE. This means that the total flux of D ψD is q.
From the above, my understanding was that the D field was independent of the medium through which is travelled. My notes then go on to describe "the distribution of flux through non uniform media" which uses as example of two large blocks of different permittivities ε1 and ε2. In this example, the problem that I have with it is that the the E field in medium 1 - E1 is equated to E2 in medium 2 such that E1 = E2 = E. All further derivations in this section stem from this. From what I have mentioned above, I dont see how it is possible for E1 to have the same intensity as E2 if the media have different permittivites? I would have thought that a good starting point would have been to equate the D vectors instead.