for academic purposes I'm  doing a very specific task where i need to calculate the Cell Constant of an American Non-Polarized Plug, ie, without  same length the prongs.  So I need to know what are the dimensions of it, namely, length, thickness,wide and distance between the probes.   I cannot get the dimensions for this plugs anywhere on the internet , only from polarized ones,  so if any kind soul with one at home could give I would be very appreciated.  Thank you.
123085
I am trying to find the dimensional tolerance on US electrical plugs. I have tried looking online, but I have only been able to find that they are called , and have found the picture below showing length and height for the male connector (but not width of the male prong), and I haven't been able to find dimensional tolerances anywhere.     I ask here because I'm assuming there's a US code that governs electrical plugs, but I can't seem to find the standard anywhere.
42981
I am looking at Griffiths introduction to Electrodynamics 3rd ED.  Problem 2.10 asks for the flux of $E$ through the right face of the cube, when a charge $q$ is in the back left corner of the cube.  The solution manual says it should be $\frac q {24\epsilon _0}$ but I think it should be $\frac q {6\epsilon _0}$ because each side should experience the same flux, and the face of the cube represents 1/6th of the cube.
85213
I have only lengths for the sides of an irregular polygon, can anyone tell me how I can measure the area of the polygon? Remember only lengths of all the sides, no angles or coordinates. Few forums mention about trangulation of the polygon etc. But I only have side lengths. Does anybody have any feedback?
8113
gives a table of certain constants in different systems of units. I noticed that in Gaussian and electrostatic CGS the value of $\epsilon_0$ equals the dimensionless $1$.  I wondered whether anyone could provide justification for this? I was under the impression that $\epsilon_0$ is not even necessary in these units since it's essentially just a dimensional conversion factor in the SI, however I suppose it would still be possible to convert it into CGS units. How is this done?
52820
The first question that comes into my mind here is whether any cylinder that touches(at 4 pts) the circumference of the sphere and does not go out of it, has equal volume?   Second, how do i mathematically limit the volume of the cylinder to be less than that of a sphere? Squeeze theorem?   Please help, thanks!
51019
How can one determine the length of the different units (measured 1ex, 1em, 1in, 1pt, 1bp, 1dd, 1pc) in mm?
14770
What is the formula for capacitance of two non parallel plates at an angle with each other?If the plates were parallel then the value can be calculated as (PermittivityX area of one plate)/distance between them.But what happens in case the plates are tilted at an angle?The question came to mind while trying to understand electrostatic separator.What would be the derivation of the formula for capacitance of two non parallel plates placed at an angle? I did get a method from  Equation 6 from the above link above helps but it is independent of the length of the plates which doesn't seem likely.
3060
Don't let the simplicity of this diagram fool you. I have been wondering about this for quite some time, but I can't think of an easy/smart way of finding it.  Any ideas?    For reference, the Area is:  $$\bbox[10pt, border:2pt solid grey]{90−18.75\pi−25\cdot \arctan\left(\frac 12\right)}$$
26805
I'm looking for an equation to find the tension on the ends of a cable suspended between two poles (one higher than the other) with no load but the cable itself.    I determined that the tension would be different on each end, that the shape of the suspended cable would be a  truncated at one end, and that the following would be the variables necessary in the equation:   cable weight cable length vertical distance between ends horizontal distance between ends   Some links that could be helpful:
56492
I am self-studying electromagnetism right now (by reading University Physics 13th edition) and for some reason I always want to understand things in a crystalclear way and in depth. Now look at this simple RL-circuit:    I am assuming the wire is superconducting and suppose at $t=0$ the switch is turned on. My problem is that I want to come up with this differential equation for this circuit: $V-I\cdot R=-L\cdot \frac{dI}{dt}$. I know that I can't use Kirchoff's voltage law $(\oint  \vec{E}\cdot d\vec{l}=0)$, because there is a non-conservative electric field near the inductor. Therefore I use Farayday's law of induction: \begin{equation} \mathcal{E}=\oint_{\Gamma}  \vec{E}\cdot d\vec{l}=-\frac{d}{dt} \int_{S} \vec{B} \cdot \hat{n}\,dA \end{equation}  where $\Gamma$ is a closed loop and $S$ is the open surface attached to the loop. Now, my textbook says:     In general, the total field $\vec{E}$ at a point in space can be the   superposition of an electrostatic field $\vec{E_c}$ caused by a distribution of charges at rest and a magnetically induced, nonelectrostatic field $\vec{E_n}$. That is $\vec{E}=\vec{E_c}+\vec{E_n}$.   Inserting this in Faraday's law I get:  $$\oint_{\Gamma}  \vec{E}\cdot d\vec{l}=\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}+\oint_{\Gamma}  \vec{E_n}\cdot d\vec{l}=-L\cdot \frac{dI}{dt}$$ Now by definition: $\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}=0$ since $\vec{E_c}$ is conservative. This gives: $\oint_{\Gamma}  \vec{E_n}\cdot d\vec{l}=-L\cdot \frac{dI}{dt}$, which is perfectly fine and consistent with my textbook. However it also gives (going counterclockwise in circuit): $\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}=-V+I\cdot R=0$ which it shouldn't. I think my flaw is here, but I've tried to think about this this whole day with no succes.  I have my inspiration from Walter Lewin's video:  but I still can't get the equation by Faraday's law.  Any help is greatly appreciated.
19584
I have built a scintillation detector. The detector outputs 0,1 ms 50-200 mV negative pulses from a photomultiplier (DC). The pulse shape is shown in the picture below.     To detect the pulses I need to change their properties (still DC however). Their new shape has to be pretty much identical, but more than 500 mV positive voltage (their duration can be 0,1 ms to 0,5 ms, but preferably 0,3 ms to 0,4 ms). The shape is, again, illustrated in the picture above.  Does anyone with more experience than me have a small form-factor schematic that will work? If I need to, I have a 5 V rail that I can power something with.   Thanks!    Update: The op amp that I chose () has sufficient properties. However, I can't get my schematic to work. See the picture for my schematic.   The output I am getting is my Vcc+, which is odd. I am not getting the pulses that I was looking for. I think I did something wrong, does anybody have any ideas?    Thanks!
109665
Is there a mathematical formula between wire size, current, temperature and wire type(Or resistance)?
20829
I'm sure this information is somewhere around the internet, but I can't find it.   I have a device that takes a DC barrel jack. I don't know the polarity it expects though. There is a marking though. It looks like this:  ___ ---  12VDC   I'm 99% sure it's a symbol to indicate the polarity, but which is it? Positive inside or positive outside?
32066
I'm redoing some of the outlets in our house, as they are pretty loose. Some of these have been really easy, but I came across one today where there were 3 hots and 3 neutrals. All 3 were going into the quick-connects in a outlet which looks like this:     Don't mind the destruction on the quick-connect in the picture, as I broke that taking the wires off and am not re-using this outlet. My new outlets look like:    For my other installations I've been using the screws on the side rather than the quick-connects, but since I had 3 hots/3 neutrals I figured I'd try to put 4 on the screws and the other 2 in the little quick connect holes. However, this plan doesn't work because it seems that the wire is too large for the quick connect holes on my new outlets (maybe a 14 gauge vs 12 gauge difference? )  What do I do in this situation? Do I nut two of the hots and 2 of the neutrals together? If so, can I determine the exact type of nut I need with my wire stripper (AWG of the bare wire correspond to the gauge of the wire or do I need to include insulation?).  Edit: A picture of the sides of the outlet I'm replacing, in which it looks like the tabs are present:
111942
I have this formula for the current based on conductivity but I cannot see the influence of the gate voltage. What does it change ? Is it the value of the conductivity that must be shifted as the potential barrier of the channel is shifted ?  Thanks
50886
For some reason whenever I play with a multimeter it always gives me results I never expect. In this case I am attempting to measure the current of a AA battery. I have the multimeter set to 10A on the dial and connecting red to the negative end of the battery and black to the positive end, giving me a reading of about +6.8. However if I switch the dial to 200mA with the same connections the reading goes off the scale but with a negative number, -1. Is this behavior normal? It is a digital Southwire 10030S multimeter.  After testing with an analog meter putting negative to negative and vise versa I get a positive reading of about 5 amps though the gauge gets stuck usually. It says PRIME Cleveland Ohio on the back.    Looks like I had the fuses in the back swapped with each other and after correcting it is now matching the readings of the analog meter :D
120613
\begin{table}     \begin{tabular}{|l|l|l|l|}     \hline     ~                 &amp; Horns rev 1 &amp; Horns rev 2 &amp; Anholt \\ \hline     Antal møller      &amp; 80   &amp; 90 &amp; 111    \\ \hline     Effekt pr. mølle  &amp; 2 MW   &amp; 2.3 MW  &amp; 3.6 MW \\ \hline     Areal             &amp; 20km$^2$ &amp; 33km$^2$  &amp; 88km$^2$      \\ \hline     Samlede effekt    &amp; 160MW  &amp; 209MW &amp; 400MW \\ \hline     Effekt pr. areal  &amp; 0.008 MW/m$^2$ &amp; 0,0063 MW/m$^2$ &amp; 0,0045 MW/m$^2$ \\ \hline     Km kabel          &amp; 55  &amp; 72  &amp; 185 \\ \hline     kWh-pris          &amp; 48 øre &amp; 51.8 øre  &amp; 105.1 øre\\ \hline     Pris (mia. kr.)   &amp; 2  &amp; 3.5 &amp; 9     \\ \hline     Rotordiameter     &amp; 80 meter &amp; 93 meter  &amp; 120 meter \\ \hline     \setlength{\unitlength}{1mm}         \makebox (16,40)[t]{Formation} &amp; \raisebox{0mm}[42mm][1mm] {\includegraphics[width=0.3\textwidth, height=40mm]{Horns_rev_1.png}}     &amp; {\includegraphics[width=0.3\textwidth, height=40mm]{Horns_rev_2.png}}  &amp;     {\includegraphics[width=0.3\textwidth, height=40mm]{Anholt.png}}  \\ \hline     \end{tabular}  \end{table}   Insert text here  I can't seem to find an answer that is working for me