Electrical Definition and 1000 Threads

I'm having trouble seeing how electric potential energy production on a conductor follows conservation of energy. Let's use the photoelectric effect as an example. A photon with energy E = hν strikes a conductor, ejecting a photoelectron with a maximum kinetic energy of hν - φ. Assuming the...

I'm interested in what kind of energy has electric current ?. For everything I taught in school should have kinetic energy because electrons are on a certain potential within the electric field when the switch is closed then the electrons move and the electric current is "generated" which then...

The following circuit was created. I would be very grateful if you could check that the what I have said about it is correct. "A phototransistor was connected in a series circuit as shown below. It is used like a resister in this case with a battery and multimeter measuring current. When the...

Greeting . how electrical energy can be power over time when electrical energy is actually potential energy . from a lot of sources (wiki ,study.com..) comes the information that electric energy is potential or kinetic energy in other sources is said to be electric power p x t so i am...

Homework Statement Homework Equations V = I.R The Attempt at a Solution 6 ohm and 3 ohm are series = b Then b pararel to 9ohm = c = total resistance b = 9ohm c = 9/2 ohm I = V/R I = 9.6/c I = 2,13 A Can you help me? Is it right? My friend's answer is 0,8

Hi all, An interesting old device for you, circa 1984. It comes in a nicely varnished plywood cabinet: To restore it, I had to do some cabinetry to fix some broken seams, and a relay had gone bad inside. All working now. On the inner lid is a sheet with full operating instructions. On the...

Hi guys, can someone please have a look at the following problem that I am struggling with; An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 ohms, and the field resistance Rf is 40 ohms. The field winding consists of 1500...

Given the circuit, I am supposed to find the total resistance, but I am unsure of what to do without having a voltage or current source with an internal resistor.

Homework Statement I need help with part b- A buck regulator is supplied from a 12VDC source and outputs 5VDC at 4 A with a PWM switching frequency is 100 kHz. Answer the following then: a- Determine the continuous conduction mode inductance (L_CCM). b- Compute the inductance for the...

I’m hoping that I can find some career advice that can shine some light on my situation…I served in the Navy where my primary duty was working with the ships radar and communication systems as well as providing support with other electronic warfare systems. When I discharged from the Navy I got...

Homework Statement A circular loop of radius a and resistance R is placed in a changing magnetic field so that the field is perpendicular to the plane of the loop. The magnetic field varies with time as B(t) = B_0 * e^(-t) where B_0 is a constant. Determine the electrical power in the circuit...

I recently watched this Varitasium video where he explains the magnetic field due to a current carrying wire. In the video he explains how what we see and describe as the magnetic field produced by a current carrying wire is actually just a electric force caused by the an imbalance of charges...

I've had a side project in mind for a while involving motorized Rollerblade wheels, however I need to figure out a motor size that would give me the needed torque to actually accelerate 250lbs up to 25mph. I realize even a 5hp electric motor is large but I was wondering if ohms have any affect...

Homework Statement A 10-km-long underground cable extends east to west and consists of two parallel wires, each of which has resistance 13 ohm /km. An electrical short develops at distance x from the west end when a conducting path of resistance R connects the wires (Fig. 27-31). The resistance...

Hi. Maybe you can help me. I am reading history of physics, especially the moment when Maxwell completes Ampere's law with the displacement current. My doubts are about propagation in a vacuum. 1. Can I say that in an electromagnetic wave there are several undulating fields, one of them the...

how does electric motor convert electrical energy to mechanical energy. Hello I do not understand the following electric power is P = V * I electric motors operate on the principle of repulsion and attraction of magnetism. What confuses me where that power ends because as far as I know, the...

I have a silly question. In a simple electrical circuit, we know that the two ends of the wire are connected to different potentials of a battery through the load. Potential difference causes the current flow. But how the wire comes to know that the other end of it, is connected to different...

Hello everyone! I'm currently a student about to get my AA degree at the end of the semester so the time has come for me to transfer from community college to university and, most importantly, decide on a major. Throughout my college career thus far, I've bounced around with ideas like...

I want to study "Electrical Machines" Course. I looked for online courses but they all had different prerequisites to study "Electrical Machines" course. Can anyone guide me about what prerequisites are needed to study "Electrical Machines" or any specific contents that i should study (e-book or...

Could we calculate (linear) electric polarizability from Berry phase?

Hi, In some marine isolated electrical systems I saw that only one phase insulation resistace is monitored. Why? If something happens on other phases I will have no information about that or...? Regards!

Recently I asked why with a multimeter you should not measure the resistance of a fuse in a car while there was still power reaching the fuse but why it was ok to measure the voltage. I was told the way resistance is measured is a small current is sent by the meter for the calculation to be...

Homework Statement Homework Equations V=IR kirchoff's Voltage/current law The Attempt at a Solution Going off the answer i got correct, 65V / 138.1788Ohms (Req of total circuit) for a total current of .47A. I think this is where i messed up but don't know how to continue...

I'm 24 and graduated with a masters degree in electrical engineering in the UK last year. I had it in my head that I would get a masters degree and then get a graduate training scheme position in something like power/energy and enjoy it while earning decent money, but I haven't been able to get...

Hi I watched this video of a guy testing a fusebox with a multimeter: if you skip to 6:10 he uses a multimeter on a particular fuse and when putting the black lead on good ground of car and red lead on either side of the fuse he gets the same reading on both sides. He even comments that there...

Hi, when it comes to Transformer Oil testing, there are some parameters that we need to consider but i don't understand their definitions and i can't find their explanations online, so may someone please define these terms for me that what these terms actually mean? the terms are as follows...

Homework Statement I have some data from measuring EC in solutions and I don't know how to convert EC to pH Homework EquationsThe Attempt at a Solution I use Arduino for programing. Values of ADC of EC that I collect from microcontroller are 80 ( for EC : 0.2mS/cm ) , 90 ( for EC ...

Why does an increased electrical permittivity reduce the phase velocity of light in a medium? Furthermore, what interactions do we see on an atomic level? I am aware of the equation that defines the speed of light in terms of the electrical permittivity and magnetic permeability, but I do not...

Why does an increased electrical permittivity reduce the phase velocity of light in a medium? Furthermore, what interactions do we see on an atomic level? I am aware of the equation that defines the speed of light in terms of the electrical permittivity and magnetic permeability, but I do not...

Homework Statement An electron that accelerates from a point near a collection of negative source charges toward a point near a collection of positive source charges experiences A) a decrease in electric potential energy as it moves toward a region at a lower electric potential B) a decrease...

Homework Statement The circuit of FIGURE 2 shows a 10 kΩ potentiometer with a 5 kΩ load. Determine the position of the slider on the ‘pot’ when the voltage across points ‘XX' is 3 V. Homework Equations The Attempt at a Solution I really don't know the right way to start this. If I'm being...

Hi. This might be really basic. But I am really struggling to grasp the difference between electrical currents such as AC and DC and RF. For the case of AC current, it alternates currents at a certain frequency.. which makes me wonder how AC and RF are different. Also, if you could, could you...

Hey guys, I as wondering what happens to an insulator during and after electrical breakdown. I understand that at a high enough voltage it exceeds the dielectric strength and becomes a temporary conductor. However, what happens afterwards. Is the material deformed or does it still maintain...

I am going back over the topic of electricity and energy. I am just wondering within a kinetic energy generator what is the relationship between the speed of the rotating shaft and the overall electrical output of the generator. Thanks

I'm on a sticky situation right here. I have almost completed my third year of a mechanical engineering degree and I'm just now realizing that I would prefer working with embedded systems/software. This happened after I start toying around with an Arduino and learned C and Python for fun's sake...

I am an electrical engineer, and I know that my question is not directly relevant to the pure Physics but anyway, my question is that how electric signals move inside wires? how to initiate the electrical signals knowing that in order for the electron to move in a circuit, we need a continuous...

Hi Everyone, I was just learning about action potential generation via electrochemical gradients. I was just wondering, does anyone know whether a +1 unit of concentration gradient is stronger/weaker than a +1 unit of electrical gradient? For example: If side-A of a split chamber had a net...

So, I am majoring in Electrical engineering, and probably doing a decent amount of Physics and Computer science courses until I can no longer squeeze it into my schedule. In the far future, I definitely plan to work in industry, and hopefully in R&D type engineering work. Will I ever in my...

My hope is to explore [the existence of] dynamic correlation of plant tissue (leaves to start with) electrical resistance to stimuli. I've heretofore conducted experimentation reasonably sure enough of the techniques and materials I'll need that I've never posted for such advice in a public...

So I have been watching his videos trying to get ready for second year engineering (electrical). However, I am very confused as to what exactly is going on when he is pressing the enable/pulse switch during the run-through at 14:45. He has the enable connected to a capacitor, and he calculates...

Should be a simple question. Hopefully... Buoyant object rising in water pulls on a cord attached to a generator. How much power is generated? Object Volume = 100m2 Liquid is plain water = H2O Depth = 100m I understand that Archimedes Principle is the buoyant force = the weight of the...

Homework Statement Consider the arrangment of charges (fixed in place) shown in the figure. The square has side length d. (Figure 1) Now suppose the particle with charge q is released. It is "kicked" so that it's initial speed is v. After an unspecified trajectory, it is observed that the...

Homework Statement "In an early attempt to understand atomic structure, Niels Bohr modeled the hydrogen atom as an electron in uniform circular motion about a proton with the centripetal force caused by Colomb attraction. He predicted the radius of the electron's orbit to be 5.29x10^(-11) m...

Homework Statement A 90 μC point charge is at the origin. Find the electric field at the point x3 = -35 cm , y3 = 80 cm . Express your answers using two significant figures. Enter the x and y components of the electric field separated by a comma. Homework Equations E = kQ/r^2...

Hello here, Please, what is the minimum spacing between sockets is based on the BSI standard or any other standard being used in the UK. I was wondering maybe there is such specification just like in the NEC which required 12 feet between sockets. Also please, is there any major difference...

I read that the Tesla electric motor is able to achieve its remarkable power to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline engine, because it tightly winds its copper wires in its coils therefore being able to carry more current in the same space. If so, then we...

If my professor tasked me with finding out where to find the materials for setting up an electromagnetic ring expansion test, where is a good place to start? Generally, what is a good procedure to follow when setting up an experiment? I am not very experienced but I would like to learn. The...

What is a thyristor and how do they work?

I'm not sure if this is the right thread to post this, but here it is! I'm currently trying to create a prop for one of my friends, since I found it an interesting challenge. This is a simple drawing of what I'm trying to do: The button, battery and so on it not my problem, it's that I've no...

Homework Statement here is my problem : Homework Equations like usual, the problem is related with RLC circuits and transients The Attempt at a Solution [/B] from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4...and from the...