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I don't know how this "paradox" can be solved. I'm given the following system: A permanent magnet with a magnetic field given by ($\hat{a}$ are unit vectors in the x and y directions) $$\vec{H}=H_0\... 1answer 772 views Is there something like the Poynting vector for hydraulic circuits? The Poynting vector is a representation of the energy flux in electromagnetics, showing the amount and direction of power flow at different points in space. In electric circuits, the energy is not ... 1answer 523 views What is the Poynting vector of an electron? On chapter 27 of "The Feynman Lectures on Physics Volume II: Mainly Electromagnetism and Matter", Richard Feynman says: Finally, in order to really convince you that this theory is obviously nuts, ... 3answers 350 views Question about intensity of EM waves For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of http:... 1answer 71 views Why does the divergence of the Poynting vector have energy flux density? The poynting vector is defined as \vec{S}=\mu_{0}^{-1}\vec{E}\times \vec{B} Taking the divergence of the poynting vector, one arrives at \vec{\nabla} \cdot \vec{S}=-\frac{\partial u}{\... 2answers 197 views Near Energy In the Null of a Hertzian Dipole Since \mathbf E = -∇Φ - ∂\mathbf A/∂t one expects an oscillating \mathbf E field even in the null of a Hertzian Dipole unless the two right hand side terms cancel -- which they do in the far field ... 3answers 524 views Poynting's theorem - energy conservation Poynting's theorem:$$\int_V\left(\vec{E}\cdot\vec{J}\right)\,\mathrm dV = -\dfrac{\partial}{\partial t}\int_V\dfrac{1}{2}\left(\epsilon_0 E^2 + \dfrac{1}{\mu_0}B^2\right)\,\mathrm dV - \dfrac{1}{\...
The vector potential of a Hertzian dipole falls off spherically as $1/r$. The polar axis of the dipole is a "Null" field -- meaning no electric and magnetic field. The absence of magnetic field is ...
If the electromagnetic field of an unpolarized plane wave is written as $$\bar{E}(t,\bar{x})=(\bar{E}_{0x}+\bar{E}_{0y}e^{i\delta(t)})e^{i(\bar{k}\bar{x}-\omega t)}$$ \bar{B}(t,\bar{x})=\frac{1}{\...