Electrical Definition and 1000 Threads

Homework Statement The problem is to create a small alarm that will buzz approximately 6 seconds before it stops buzzing. I managed to create a working alarm, only problem is mines will buzz for around 1.5 seconds not six. Homework Equations τ = RC V = V0e-t/τ The Attempt at a...

I'm working on a project were I will be using Heating Plug Element- http://www.omega.com/ppt/pptsc.asp?ref=CSS_CSH&Nav=head01 I want to be able to control temperatures up to 1000 F using something likes this: http://www.omega.com/Manuals/manualpdf/M4636.pdf I would like to be able to...

How does one find the electrical resistance of a homogenous sphere of uniform density? By connecting two wires across the diameter of the sphere, and assuming Pouillet's Law R=ρ\frac{L}{A} holds.

Hi guys, I've been using your forums for quite a while to help reinforce my physics principles, and only just made my account. I wanted to know if there were any electrical engineers that would be willing to assist me with some guidance in a small design challenge. Homework Statement Here are...

I'm wondering what are some recommended certifications a soon-to-be college grad should get as an electrical engineer besides an E.I.T.?

Between control theory, photonics/optoelectronics/semiconductor devices, electromagnetics (antennas or other application), which of these fields has the potential to expose me to the most mathematics in graduate school?

1. Homework Statement d.c supply 200V capacitors A and B connected in series p.d across A is 120V p.d. across A, increased to 140V when a 3μF capacitor is connected in parallel with B. attached diagram for better understanding. Find capacitance of A and B. 2. Homework Equations...

Homework Statement ive tried many things and can't seem to grasp the concept of KCL.i know the node I am looking for is between r1 & r3. i assumed i1+i2=i3. also looking for directions of currents. V1=30v V2=40v R1=82 R2=68 R3=47 Vx = ?Homework Equations i1 + i2 + i3 = 0 ? The Attempt at a...

hello, I'm wondering the difference between electrical engineering and electronics engineering. Or are they the same but just some universities call it differently?

I have an exam on monday, for a course I'm not familiar with. I have studied the material and tried some example exam question but I can't seem to figure out how to get to the result of the following questions. Q1: Homework Statement A sample of hydrogel is in equilibrium with a sodium chloride...

Homework Statement A simple series circuit has an inductor of 1 henry, a capacitor of 10^-6 farads, and a resistor of 1000 ohms. The initial charge on the capacitor is zero. If a 12V battery is connected is connected to the circuit, and the circuit is closed at t=0, find the charge on the...

I'm sorry to be annoying on this forum, I am new to the physics world! I am an undergrad taking physics I but am also doing a directed study on acoustical physics, sort of. I just need to write a paper on something along the lines of acoustics and their uses in communicative devices like...

Hi all, I'm trying to understand the electrical model of a neuron, and I have 2 questions. I'm a little confused about the time constant in this electrical model of neuron recording: The time constant shown is tau = C*(Rm*Rs)/(Rm+Rs), which implies that the resistors are in parallel...

Hi all, I have been looking the electrical symbols for a proximity sensor and a level sensor. A simple google search has not helped and I have also looked at various manufacturers websites, but still no joy. I was hoping somebody could point me in the right direction to a comprehensive list of...

I'm currently an "exploratory engineering" major at the university- which pretty much means I'm still taking interdisciplinary courses and haven't chosen a discipline yet. I want to continue with my engineering education but I'm also interested in physics. The college of engineering offers...

Hi, 1) How does the electric circuit variables such as Voltage, Electric current, and Resistance vary between two frame of references? 2) Based on (1): If someday we build a spaceship that move with very high speeds, are there issues to consider regarding the electric circuits in the ship?

Homework Statement The electron concentration in silicon at T = 300K is: n(x) = 1016e(-x/18) cm-3 where x is measured in μm and is limited to 0 ≤ x ≤ 25. The electron diffusion coefficient, Dn = 25 cm2/s and the electron mobility is μn = 960cm2/Vs. The total electron current density is...

Calling in all Electrical Engineers- Final Year Project help needed! I needed some help from you guys regarding my Final year project. Basically my project is about a hydrogen fuel cell that charges the batteries in cars, its a hybrid system. The fuel cell is PEMFC (proton exchange membrane...

Is there any known method to convert straight into electrical energy? without all that 'steam' part? xD

I get very confused with AC electrical service, I'm a mechanical engineer so these things just confuse me. DC makes perfect sense to me. Anyway, I need to supply a single phase motor with 230V (the specs say 230V +/- 10%), so that would make my tolerance 207V to 253V. The motor is for a...

I have a question to depth understanding electricity what's the thing that make electrical power appear? I mean that when generating electrical power We generate emf (voltage) and if the circuit was closed we get current ! HOW THEN ELECTRICAL POWER APPEARD AS AN IMPORTANT PARAMETER

I was wondering if there was a simple program out there that would help me design and toubleshoot schematics I draw? For example, I have a schematic for a power supply that takes a 6.5k "core and coil" transformer and ups the voltage to 15k to supply a Van de Graaff generator. Now, the problem...

Please see the following question and the answer. I don't understand how Fe/Fw = 0.12/0.43 Question? Two small metal-coated styrofoam spheres each of mass 2.80e-6 kg are attached to nylon threads 45.0 cm long and hung from a common point. The spheres are then charged equally negative and...

Hi everyone! I wanted to know why in the circuit analysis a generator doesn't represent an electrical branch? And the second question is if two resistors are in series on a wire, does it represents only a branch(the series of the resistance) or two branches ?

Hi all Sorry if this is quite a basic concept, but I am confused about RF signals. The way I currently understand it is that radio waves in space are an oscillating electric and magnetic field at 90 degrees to each other traveling through a medium. However, when you pass a radio wave into a...

Hello, I would like to hear from people who have first hand working experience(have been employed) what are they doing(a typical day in the office) on the following fields: a)Systems Engineering b)Embedded systems Engineer c)Robotics,systems and control d)analogue and/or digital design...

hi everyone i have a lab due tomorrow and wondering if someone can help me with question b. See attachment. I have done the k graph and got my boolean equation c'd+bd+b'cd'+ab'd. i just simply can't make the circuit. i have to use only and or gates. can someone please help Not sure if you can...

Hi, I'm trying to understand electrical potential and potential difference. I was wondering if anyone can confirm if what I have written is correct or not? If not I would be glad to learn what I am yet not understanding. When you push away an electron of negative charge from a positive...

Homework Statement Four charges, q1=+q, q2=-q, q3=+q and q4=*q are at the corners of a square with the side a=7.5 cm. (In such way that if one travels along the perimeter of the square, the charge signs are alternating.) If q=3.0 μC, what is the total energy required to assemble this system of...

We all know the coulomb's law of electrical force between two charges q_1,q_2 equals to \normalsize F= Kq_1q_2/d^2. But this law is not precisely true when the two charges are moving. We know for a single charge q moving with a velocity v the force is \ F=q(E+v×B) What is the straightforward...

I've been asked to prove KVL and KCL using this circuit, but my vectors don't add up. ei Vr1+ Vr2 + Vc1+Vc2 ≠ Vtotal, same goes for Current, but I at least got the correct angle for the current Tried using vector addition, using addition of the vectors in complex form and even tried using this...

Homework Statement Given I0=-2 A I1=-4 A Is= 8 A Vs= 12 V Find all the unknown currents. http://sphotos-a.xx.fbcdn.net/hphotos-snc7/398253_493549703997883_2004542070_n.jpg Homework Equations Kirchhoff’s current law The Attempt at a Solution I start at node a and found I2= 6 A and then...

Are there opportunities for EEs to be involved in research on antimatter engines? Considering antimatter engines are heavily based on magnetic principles, is it feasible to assume that antimatter engine design will be a subfield of EE? The gap between EE and theoretical physics is getting smaller.

I'm currently enrolled in a PhD program in control systems engineering. I'm wondering what tends tend to be the most useful subsets of this field, and consequently the most important to be well-versed in. I've read Kalman filters are very important in real world applications. Optimal Control and...

Homework Statement Here's the question: http://puu.sh/171ls The Attempt at a Solution I have no idea where to begin. It says R(AB) = R(L) = 301 ohms. What does that mean? Does R(AB) mean the resistance from A to B? Is that the total resistance? The total resistance is equal to 301 ohms which...

Homework Statement Calculate the fault level for a 3Ø fault at F With bus section CB closed With bus section CB openHomework Equations The circuit diagram can be found here http://s1167.photobucket.com/albums/q629/sayeen1/?action=view&current=fault_level.png The Attempt at a Solution The...

Can someone please explain in a detailed manner about skin effect in electromagnetism, particularly wanted to know why does this effect take place??

Homework Statement Your first assignment with the Holmes Electronics Company is to help us design an efficient stove using resistive heating. Our market research tells us that the stove needs four heat settings: Hi, Med-2, Med-1, and Low. The Hi setting needs to have an electric power of 3...

Hi I am thinking of ways how to transfer electricity so that I can separate the phase magnetically or otherwise, Ok we all know transformer is one way to do it but it's big with mains frequency, other would be pulsed DC in an smps , but that's is already a very tried idea, is there any other way...

Hi there, I am supposed to measure the electrical impedance (which depends on conductivity) of an electrically conducting object by use of eddy current technique induced by an air core coil. for this purpose I need to print a circuit. would you please help me with the characteristics and out...

Homework Statement I've been reviewing my electrical theory and I'm having trouble trying to calculate an expression for the voltage gain for these two specific circuits. (Images c and d of the question.png attachment). I already know the answers, however I am unable to derive the same...

Homework Statement I should find i1 and i2. Homework Equations V = R*I KCL KVL The Attempt at a Solution I have no idea where to even start, so I tried doing different things, but nothing that I do works. I am just really frustrated right now, for failing at doing such a simple thing. I...

Sorry if the title is slightly misleading, but I'm having a hard time trying to develop a better understanding of electric current and electrical energy. Basically, I understand that, say for example, a potential difference across a circuit creates an electric field, which in turn causes the...

Homework Statement Figure 21-34 shows electrons 1 and 2 on an x axis and charged ions 3 and 4 of identical charge q and at identical angles θ. Electron 2 is free to move; the other three particles are fixed in place at horizontal distances R from electron 2 and are intended to hold...

Hi, I have finished my bachelors in electrical engineering and now I will continue with masters in the same area, specifically in telecommunications/signal processing branch. I would not consider my mathematical background too weak, I have good knowledge of calculus and linear algebra. In the...

I definitely want to do some kind of r&d with my degree so I am planning on graduate school. Now I've heard that you need some kind of physics along with ee to do the real new development type of stuff, kinda like creating new and improved components and processors ect. Doesnt engineer mean to...

SO i am trying to figure out how much electricity can be produced through elector magnetism. I figure the information needed would be 1.Density of the magnetic field. 2. The # of coils in the solenoid 3. The rate at which the solenoid passes over the magnetic field. 4. The distance the...

Hello everyone, I am a 36 year old Master Electrician and I'm thinking about going to to for Electrical Engineering. Is there anyone who may have any information on a transition such as this? I guess I'm looking to do as much of this as I can online, if that's even feasible? What classes should...

Hi all! I'm studying electrical generators, and while I was trying to come up to the expression of EMF induced in a conductor I got two different results following two different ways, and I can't find the error. With sinusoidal B, with e=bvl I get an RMS value E=2K_{f}f\phi, while with...

When i think of electromagnetic waves i think of a fast moving sphere of expanding or contracting fields,either magnetic or electrical depending on where its at in its cycle. So i guess I am picturing a single photon as a sphere. Is this a correct visualization?(i doubt it). If so, how does a...