Recent content by Jelsborg

Clever redrawing - I'm getting the same as my simulated value out of this circuit. Thank you very much!

Then I don't really get how to evaluate the R22-R19 connection. They both meet at the A3 node, which also meets R23, while the other end of R23 meets the node connecting R24 and R21. So I'm trying to convert the whole R24-R21-R19-R22 into one resistor which I can then consider as parallel to R23...

Since the voltage and thus the current over ##R_{20}## is then 0, right? Moreover, is this reasoning correct: R21 and R24 are in parallel with the series of R19 and R22, which is then in turn in parallel with R23?

I am asked to find the Thevenin equivalent for the circuit above. I already got the equivalent voltage by node analysis on the nodes B and A3. What I'm trying to do is to zero the 10V-source and then calculate the equivalent resistance between A3 and GND. Whatever expression I come up with...

In a recent test we were asked to calculate the electric field outside a concentric spherical metal shell, in which a point dipole of magnitude p was placed in the center. Given values are the outer radius of the shell, R, The thickness of the shell, ##\Delta R## and the magnitude of the dipole...

Yes I am now considering the case ##V_{2}(r)##. So my understanding of this problem is now this: As ##R \rightarrow 0## in Method 2, this corresponds to the case where the charge density (which is negative) is non-existant as it simply has no volume. Conversely, letting ##r_{1} \rightarrow 0 ##...

Since Method 1 in this case yields a negative charge -q0, does that mean that this method fails to find a positive charge q_0 (which was previously the spherical shell of radius r1), thus inferring that the point charge in question is positive? This would kinda make sense to me as the limit as...

Well yes in that case the first method gives 0, while the second method yields q_0. Where q_0 is the obvious choice for a right answer. Mathematically it seems pretty obvious why this happens I guess. The physical meaning is where I get lost. I'm thinking that there's some kind of unfulfilled...

So the first problem stated is to show that for a charge distribution between two spherical shells of radii r1<r2, the total charge inside is described by: This is rather trivial using Gauss' law in integral form, so I regard this as completed. I have used the gradient to find the electrical...