Current Definition and 1000 Threads

In a normal circuit it's easy enough to visualize the path electrons take through a wire. Even considering leakage current in a capacitor, it's easy enough to visualize a large parallel resistance that current "leaks" through. Is there such a way to visualize corona discharge? I get that it...

The resistors are all in series , with exception of R, so I added them together and then used the current divider equation to solve for R, and I got 720 ohms. The textbook says R should be 30 ohms. I’m completely lost.

Hi, I was trying to read about the current produced by a dynamo in my physics books but I can't find any reference. I have a rotor rotating at a certain speed, air flow and with a certain inertia, but how can i find the power produced and related current and tension?

I'm an EE with only a surface knowledge of solid state. I know this forum is mostly for students but I don't know where else to find a lot of physicists. Also, please forgive me if this is a dumb question. For a circuit I want to build, I need a transistor that can conduct > 10,000 A, but does...

To my understanding, current density is simply the current flowing through the alkaline electrolyzer divided by the area (the units for current density are A/m^2). But what would the area be in this situation? Is it the area of the electrodes or maybe the area of the electrolyte solution or...

e=QxV t=Q/I p=(QxV)/(Q/I) =V/I The expression I came up with for a) is the potential difference divided by current to get power but I have no idea if that is even right if someone could just prompt me in the right direction that would be greatly appreciated

I am not sure if I should use the word 'current' or 'charge' but my question is whether, in a typical U.S. residential 120/240 split phase system, is the local transformer always the source to which current (charge?) must return? Or can it bypass and go direct to other PoCo elements/generators...

I check the datasheet of LM 319 high speed comparator online. I was wondering if LM 319 can accept negative supply voltage(-10V) and its possible to produce a 10V to -10V square wave which oscillates along origin rather than just 10V to 0v as shown below.

I read that "the azimuthal drift is compromized because the typical life expectancy of ring current particles is only hours to days and thus of the same order of magnitude as the drift period". But, if it is so, why relevant current exist? How could we armonize the fact that the azimuthal drift...

Hello! I'm currently working on a project which aims to study common mode current filters. What I'd like to know is how can I generate enough common mode current in order to be able to make experiment on my filter ( its efficiency to reduce it for example) I have some constraints: -the current...

Hi, there. I am interested in quantum gravity. But I am not sure how to find review papers about its recent developments. I tried "quantum gravity" on google scholar. But I could not find a suitable review other than that about loop quantum gravity. I am not sure what are the other approaches to...

Hi all, my work is shown on the attached image. The boxed equation is what I get to but I do not understand how to go from there to what the book has. I am guessing that the problem arises when trying to solve the cross product. I understand that I will need to find the value of the sine of the...

I am trying to understand the current path for corona. Assuming the corona appears on the high voltage electrode, how are the electrons actually flowing? I understand that with flashover a low resistance current path is created as the air is ionized but what is happening with corona?

So for the first question it is very straight forward. The magnetic field is going through the loop, increasing the flux through the loop. The induced current must flow clockwise in order to generate a field that goes through the loop in a downward direction to oppose the change.The second...

Without mathematical formulas, but only with a "Physical intuitive meaning", why if at t=0, I have a charged capacitor, and I connect it through a wire ,forming a closed path, to a inductor the current increasing with time and his derivative decreasing? To me seems like the inductor oppose "to...

As per ohms law the current is generated based on voltage and resistance V=IR. So if 5v and 1k resistor the current 5mA flows in resistor. But if I take a current source, can I pump any amount of current to resistor? So, current drawn is not characteristic of resistor?

I used the above equation, and started with getting the cross product of dl and r, which was equal to 0.00195i+0.00365k. From there, I divided each component by the magnitude of radius cubed (0.827^3). I then multiplied by I and u naught(u_0=4pi*10^-7), and then divided by 4pi. The answer I got...

I have a graph of mean signal (per pixel) vs exposure time (sec) for 8 different dark frames. I am being asked to find the bias in ADUs/pixel and the dark current in ADUs/sec/pixel and I am very confused on how I could get it. I know that the average of all of the mean signals is a rough guide...

I was following this problem up until they say we can they state I3= I1-I2. I understand why we can say that but I don't see how I can use that to get the system of equation in terms of I1 and I2 at the bottom. Could someone show me how this was done?

The answer from my teacher is two of these photovoltaic cells are connected in parallel. I can understand the parallel connection will produce same e.m.f but I don't understand why the total current will be greater than ##I##. I imagined one of the cell connected to a lamp. The current through...

I started a project, and where I thought I has a potentiometer position feedback, best I can tell I have an eddy current position sensor, which I'm absolutely not familiar with The application is a diesel engine injector pump (retrofitting to a different engine, it was from a Komatsu V12, no, I...

I always find voltage vs time majorly in case of AC current. What about current V time in AC current cases?

Somehow this answer is incorrect , but i realize that even numbers are hipothetical , 45 coulumbs is too much charge , what is wrong in my calculations?

Hello, I have used an edge current of 10 A through a 0,45 cm (lenght) wire inside an air sphere. The thing is that, according with Ampere law, the magnetic field (B) produced at a 1 mm of distance from the wire shall be 0,002 T, and I am obtaining much higher values in this simulation (around...

Hi,I have found in my textbook the formulas for both current and voltage and I have no idea if they are right or wrong. Can someone help me with these formulas? v=v0cos(wt) i=i0cos(wt) Is this correct? In google when I search for the answers I get something else: v=v0sin(wt) i=i0sin(wt)

Hello, I wonder if you could give me some advice to how solve this question. What I was thinking to solve it was to determine J by using Ohms law, ## \vec J = \sigma_{\alpha} \vec E ## I already determined the E field for for the sphere, I got it from a) ("a)" was to determined all the bound...

a) My idea is: 1. Find the energy created by annihilation process, which is ##E=2mc^2## where m is the mass of electron 2. Find the wavelength of photon by using formula E = hf 3. Find the speed of positron by using the formula of de broglie wavelength 4. Find the p.d by using conservation of...

I have been studying Studying Donald Neamen's Electronic Circuits 4th edition and Sedra Smith's Microelectronics 7th edition for quite some time now. I have been self studying. After searching extensively on Internet as well as trying to understand from the books, I have not been able to...

My questione are these: -If i have a voltare source (like a battery) that supplies a 5V voltage difference between its terminals, and there is a parth from positive to a resistor and then to ground, with negative terminal not connected: the current flow to the ground?( I believe because there is...

Despite its lackluster reception at its conception by Hugh Everett and subsequent advocacy by Bryce S. DeWitt the concept of "just take the theory seriously" and intriguing science-fiction concept of parallel worlds eventually gave it a major resurgence, much thanks to David Deutsch's pioneering...

I've been thinking and can't come up with a satisfying answer. Would there be a difference in the amount of heat generated in a given time in a metal rod if it was heated by a) induction b) current passing through the same length of rod Given that the current is the same amperage and...

Hi, I don't understand how to solve the problem below for (a). First I transform the cirucuit to direct current problem using jw method. Now i see that U=-I2Z. Z=R2+Zc3=R2+1/jwC3=4,5+1/[j(1000)(10^-3*0,25)]. Then I use impedance transformation to get rid of the transformator(using Z0), but then...

Before that, Lawrence Kraus stated "Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them" . After reading https://www.physicsforums.com/insights/physics-virtual-particles/ especially this statement...

Hello everyone, [I underline portions of the text that are most essential to my enquiry ( 2 questions at the bottom). I immensely appreciate the generous act of reading everything otherwise.] Background Info: North African, female-identifying, 16, below average ECs, no awards, no notable...

To determine the voltage I did voltage/number of globes: 24/16 = 1.5V per globe - Not sure if this is correct or not To determine current, I figured out using resistance formulas that the resistance for each set of 8 globes is 15 ohms R = V/I 24/3.2 = 7.5 ohms total resistance 7.5-1 = 2 * 15-1...

First of all I want to ask , do the LHC power klystrons work always in CW or are their frequency shifted to correct for timing of the bunches in the LHC tubes in case something isn't aligned or doesn't that ever happen? Also how do they drive the klystrons at LHC or other CW operation from an...

How can current gene editing technologies like Prime Editing can be used to reverse all age related mutations that negatively affect some type of cell like neurons?. According to this article (you need to click on the "toggle reader view" button in firefox in order to read it without registering...

How would you go about calculating the work done in morphing a square current-carrying loop into a circular current-carrying loop, without change in length while maintaining the same angular orientation with an external magnetic field. My book suggests defining P(potential energy) = M.B (dot...

Hello, I'm seriously confused on several things around how concretely batteries create potential difference in order to force the electrons circulate trought the circuit wire. Almost all explanations I found (wikipedia, diverse tutorials, intro scripts, etc.) explain it in nearly the same...

a) Output voltage = 2 x 6 = 12 V Current in R = 12 V / 13.5 kΩ = 8.9 x 10-4 A That is the correct answer based on the solution but I don't understand why when calculating the current in R, the resistance of secondary coil is not considered. I thought it should be like this: Current in R = 12...

The energy stored in a current loop equals ##\frac{LI^2}{2}##. From a dimensional argument, it follows that the inductance grows with the size of the loop. This would mean that, if we assume the current stays constant, enlarging the loop would require external positive work, so, the force...

Hello, I need to know why having an electric current in Prefect Magnetic Conductor(PMC) violate current conservation. Based on the boundary conditions or lorentz force or ..., I couldn't be successful to prove that surface current can violate current conservation. In the textbooks, they...

I am stumped and would like a hint. Answer choices:

Would using an insulator like rubber tires partly buried in the ground + partly protruding above the land surface to create a continuous perimeter around a piece of land possibly shield the land inside of it from the accumulation of charge on the surface of the Earth which occurs in the vicinity...

Hello. As time goes by, and as i got more near to "moderns problem of physics", i have been noticing something about it. More specifficaly, the vision of the theoretical physicist that i always had is changing. This is not necessarily bad. But here is this: While my initial vision was of...

I could solve a similar (rather, a specific case of the above) where the current entered through a corner and left from the corner opposite to it along the body diagonal of the cube. For this specific case, I was able to easily exploit symmetry to deduce the answer (0). However, I cannot think...

why does the current reverse when the coil is at this position in A.C generator ?