Recent content by Born2bwire

Your own derivation aside, do you understand how Ampere's Law is used to derive the magnetic field for an infinite DC current carrying wire?

I've found that programming questions are still good at weeding out people with poor skills or not enough experience. We still come across the occasional person that cannot put together a basic algorithm. Beyond that, I've stopped asking programming questions like those. Most applicants are...

Any two physical objects will experience the Casimir force and this can be calculated via the density of states due to the photon modes. If you consider your plate, detector, and source as physical entities, then they will disturb the photon modes by virtue of the fact that now any mode must...

The differential equations operate locally at a given point in space. While you need a charge or current to generate the electromagnetic waves, you can observe them in regions where there are no sources. The integral form of Maxwell's equations represent integrations over surfaces and volumes...

A capacitor can retain memory of a voltage and an inductor a memory of a current in a sense. For example, an integrator can be built using an opamp and a capacitor. The capacitor acts as a memory of the integral and holds the output voltage when the input goes to null. The integtal is obtained...

The divergence of the displacement field gives you the free charge, not the bound charge. So the continuity of the normal displacement field tells you that there is no free charge at the interface, not bound charge. The bound charge is the negative divergence of the polarization density, the...

I'm talking about that instance in time where the charge are moving at the same velocity, up until we allow the charges to move freely. In this case, we have a frame where the two charges are at rest with respect to each other and so the force in that frame is the coulombic attraction. If we...

I would point out that since they are moving in the same direction and speed, that we know already that the magnetic field is not going to have a net effect at that instance. If we observe in the frame of the charges, so that they are stationary, then there is no magnetic field, just the...

That's simply going to dependent on the time you allow to discharge, the inductance of the coil, and your resistance (most likely dominated by the coil). There is always going to be some residual voltage because of the diode drop. But you are talking about a miniscule amount of energy here. 10 V...

In general, you do not need a resistor between the inverter and the capacitor, but there are good reasons for having one. If your inverter is just taking the output from the rectifier then you would probably want a resistor/capacitor or inductor/capacitor to act as a filter to give you a...

If you are ambiguous about the ground, why not use a current sense transformer? Place the primary in series with the low side return and place a current sense resistor across the secondary. Only problem is that you have a small current and low frequency. Off the shelf current sense transformers...

Ok, then that greatly simplifies the whole process. But I'll expand upon what has already been stated regarding the solution. You basically start by assuming the basic solution to the waves. We can work with only the electric field since the magnetic field can be solved directly from there...

This is a three layer system and the reflection coefficient will reflect the various phase changes and guided modes that can arise. Did the problem specify a specific polarization and direction of the wave? The general solution can be found in texts like Balanis' on EM or Chew's "Waves and...

I would like to echo bhobba here too. Superposition is not saying that an electron is actually in two different places at once. It is saying that it can be in multiple states with an associated probability. But when you actually measure the system, that electron will always be found in one...

But if resistance is zero, then you have the normal lossless LC response as Steinmetz shows. When you have a non-zero resistance, the current has to exponentially decay regardless of Steinmetz's "zero" impedance condition. So you still have a resistive loss, what you do not have is a...