Electrical Definition and 1000 Threads

I have a question related to electrical load. Electrical/electronic devices such as laptop, tablets often come with SMPS. Say my laptop is rated to consume 90 watts at full load and 10 watts at idle. But my question is related to how much electricity will it consume if laptop is completely...

I have been kicking around an idea for a while about generating electricity from ocean tides. The traditional approach is to use the flow of water through a channel to turn a turbine, which essentially blocks the channel for sea life and water craft. It seems more practical to use the rise and...

My questions is about the conversion of a range of wavelengths in Hz, such as for an optical filter, in a medium different from air. Since the refractive index n is higher than 1, (let's say n=1.5) and than the value of c is almost 2x108 m/s, also the equation in the link below has to be...

Metal ball ( Figure 5) radius a = 5 cm , is surrounded by two concentric metal shell of radius b = 10 cm and c = 15 cm , and d = 20 cm and e = 25 cm . The relative permeability of the dielectric between the ball and the first shell , and between the two shells is εr is 4. Outside the outer cross...

Hi, I have a loose understanding of some things in life. This in particular regards the electrons in electrical appliances. Lets say electrons in a Geiger–Müller tube. They way it is described is that radiation interacts with the chamber wall or the gas and knocks out electrons. These electron...

Today I was over at my wife's parent's house. My wife and her mom were doing a puzzle on a work bench. My wife told me she heard a buzzing under the work bench. Her mom has hearing problems and couldn't hear it but I certainly could, it was quite loud. I looked and it was coming from a lamp type...

Hello! My hobbies are tinkering on my computer and mathematics. Physics is not bad but I do not love it like I do mathematics. I like the logic and analytical skills that it requires. I like solving problems. I recently dropped out of Aeronautical Engineering because I simply did not like over...

This might be a simple and pretty basic question, but i have not succeeded on finding any relevant info online, so hopefully someone can help me out. Is it possible to pull and actuator and it resists being pulled with a preset amount of force? What I'm thinking is e.x you have set a preset a...

hi guys, i am in a bad situation and i need some tips :( i attend the first year of chemical engineering, but i have doubts about my choice... My university gives me the way to change my course in electrical engineering, and i am thinking to change. I'm not sure that chemical engineering is a...

Hey people. First of all, I'm now in the third semester of my course in Mechanical Engineering. I have interest in aerospace/aeronautics, so there are plenty of things in mechanical that I like - fluid mechanics, aerodynamics - and that was the reason I choose this undergrad. Nonetheless, I do...

Hi everyone. In electrical engineering, when you study control theory, you're taught that electrical circuits can be used to simulate the behaviour of complex systems. What I don't understand is, what are the limitation of this sistem, and why it can't be obviouslly used in a general way to...

Hi, I am trying to do a comparison of electrical efficiencies between 2 HVAC compressors but struggling to find formulas or calculations to figure it out. Can anyone help me?

Homework Statement Questions 10&11 in pictures. Homework Equations P=IV W=VIt W=Pt The Attempt at a Solution For 10a) P=IV P=70*14= 980W. 10b) P=IV 1500=12*I I=125A (which is massive so probably wrong) 10c)P=IV 60=I*12 I=5A The 8A fuse because the current flowing through each headlamp should...

Homework Statement Homework Equations At low voltage frequency (inductors) L become short circuit and (capacitors) C becomes open circuit At high voltage frequency (inductors) L become open circuit and (capacitors) C becomes short circuit The Attempt at a Solution Part A At low frequency...

1. Homework Statement There are multiple parts to this question, but I have only got through the first 2 before getting stuck. Please could somebody give me a hand as I am really struggling :frown: (a) Calculate the phasor voltage of the voltage source and the phasor current of the current...

I've been given a copy of my friend's midterm exam from this same class from last term, and decided to take a crack at it to help study. One question type in particular really messes me up and it looks like the following. How would I go about solving these in the future? A solid insulating...

For example can an object be very conductive to electricity but be a very poor conductor of heat and vise-versa, or is a good conductor of one always a good conductor of the other and a bad conductor of one always a bad conductor of both? If they are related, then how and why are they connected...

Homework Statement Find a differential equation that describes the circuit that includes only vin and vout as variables. Homework Equations C(dvin - dvout)/dt = i vin - vout = L(di/dt) The Attempt at a Solution So the answer I got was: C(d2vout/dt2) + vout = LC(d2vin/dt2) My question is...

So I am having difficulty with the following problem; Determine the currents in the various branches. So I went ahead and assigned I names to the various branches and drew in flow directions to help me visualize the problem better. From there I created the following three equations...

I worked for the Public Utilities company last summer, and we were tasked with taking inventory around the entire city, of all the transformers. We wrote down as much info as we could about the transformers, including Serial Number and whether or not it contained PCP's. From what I understood...

Hi, I'm an hobbyist right now I'm into electric engines, simple engines for low voltage and low current applications; I have noticed that there are many variations about how and what an electric engine can do even considering only DC motors, but basically all the engines that I have examined up...

Before I start this I just want to say that I don't want to offend anyone. I am a freshman college student who is looking to apply to the electrical engineering program at the end of the year at my school. I love working with my hands and solving problems using physics and mathematics and I...

Good Evening, I am not a science "professional" nor even a Physics Graduate. I am, however, interested in anything with a science twist. I have created an account on this forum hoping that someone can answer my puzzing question... Start with the simplest circuit. Battery, switch, two wires and...

I have read that when we directly use 'W' Joules of electrical energy to heat a liquid,the maximum heat we can use to heat the liquid is W. However, when we use a heat pump Q=[COP+1]*W , and that means Q > W. Hence heat pump is more efficient and is preferred over electrical heater. Doesn't this...

First, I hope this is the correct place for this question. I am experimenting with electrical discharges at low pressure, think plasma globe, and I bought a geiger counter to make sure I am not producing x-rays. My vacuum pump is rated down to 5 pascals. The problem is that the geiger counter...

Can someone please explain to me why, a changing magnetic field can produce an electric field and a changing electrical field can produce a magnetic field. Also how do magnetic fields originate, what causes them?

Hello everyone, I have a strange question. Can complete electrical circuits be found in nature? If so, can you give any examples? And what is necessarily required (besides electricity) for a complete electrical circuit to occur, naturally or unnaturally?

So I was thinking, if the body has its own electrical currents... especially in the brain, then the brain must have an electrical field that extends infinitely. If that is the case can the brains electrical field interact with the real world and influence it. So for example if the field was...

Majored HR in college, but did nothing about it yet. To work properly, learned to use SOLIDWORKS and bit UNIGRAPHICS, to work better, started learning mechanical engineering and electrical engineering, going to be 40 old now, bit difficult, but get to proceed...appreciate your help very much in...

Hi everyone, I read somewhere that when a coil is wound on a magnetic core it's electrical length becomes longer than it's physical length. I remember seeing this formula L=l * sqrt Ue Where L= Electrical length l=actual (physical) length Ue=Core permeability Does anyone know if this is...

So the frequency in the power grid is 50 - 60 Hz depending on country's electrical standard. If I have a ~2000 watt heater that runs on 220 volts ~ 9 amps at 50 Hz, would increasing or decreasing the frequency effect the power output of the device. For example if I make the device run at 75 Hz...

How is the potential difference done? How do they make electrons move? Do they use electrical field using positive (to atract them) or negative charges (to repel them)? Do they use variables magnetic fields?

Can you suggest a free program that allows you to draw electrical circuits and export them in latex through tikz package (like geogebra)?

Hello everyone! =) I am currently a 3rd year Electrical Engineering student at a decent university, and am working towards a BSEE degree with what is currently a 3.8+ cumulative GPA. I have worked here as a paid research assistant and as a teaching assistant (an ECE lab course) for my...

Homework Statement Homework Equations -We can re-arrange circuit components into simpler orientations as long as the components' connections to previous nodes are maintained. The Attempt at a Solution -I attempted to re-arrange the loop of three resistors at the upper left region to no...

Would this be a useful sequence of classes for a physics major? http://www.ese.upenn.edu/current-students/undergraduates/minors.php

in induction motor there is air gap between stator and rotor. the air gap needs to be as small as possible. but some air gap is needed for mechancial reasons. i understand that a big air gap would reduce power factor as you'd need more magnetizing current. but are there any advantages of big...

Hello, everybody First some context: I live in Argentina and I'm a few months away from starting my first year of college. In here they make the distinction between Electrical Engineering and Electronics Engineering (and then there's also Informatics Engineering which I think is the equivalent...

I wanted to do a science experiment and it is very important that i learn the electrical resistance of carbon dioxide. From what i would guess, this may be wrong, but carbon dioxide and the atmosphere on Earth probably have a similar electric resistance due to the fact carbon dioxide already...

I'm wondering if a degree in electrical engineering is still worth pursuing today? Would it be a better choice to get a degree in mechanical engineering? Any advice on this matter would be appreciated.

Is there any standard book or source to go to for someone wanting to learn how electricity works and motors and AC and DC so they can pursue their ideas and be able to understand the theory of their electrical imaginations and how it could or could not work? I"m not wanting a career in...

Ok, I've got a project I want to try, mostly for the "why the heck not?" idea, just for the giggles, you know? I just want to see if it's even possible to do. Here's the goal: Goal: Create a complete and uninterrupted sphere of electricity. This isn't as easy as one might think. It doesn't...

Hey guys, how are you? I just have an idea but can't figure it out how to solve it. Is it possible to generate electrical energy from a (high power) transformer vibration using piezoelectrics?

Homework Statement See the picture. If at electrical resonance ##U_c=60 V## and ##U_L=40 V##, find the ratio of reactances ##\frac{X_L}{X_c}##.Homework Equations [/B]##Z=\sqrt{R^2+(\omega L - \frac{1}{\omega C})^2}## , ## Y= \sqrt{\frac{1}{R^2} + (\omega C - \frac{1}{\omega L})^2}## , ##\phi =...

So I'm a freshman in college right now and I am a physics major. The class I am also having most trouble with is...physics. I am doing great in math but physics is tougher for me. I was thinking that maybe physics isn't for me, as also looking around I realized just how theory-based everything...

Consider a system of two charges ## q_1## and ##q_2## separated by distance ##r_1##.This configuration is associated with a potential energy ##U_1##.When the separation is increased to ##r_2##.Potential energy becomes ##U_2## ##dW_E##=##\vec{F}##.##\vec{dr}##...

In my circuits/active devices course we had to make amplifier designs with various type of transistors (BJT, JFET, MOSFET). In each design the transistor beta parameter played an important role in deciding which resistors to use in the final amplifier circuit. This beta parameter changes widely...

I have troubles for designing a 3 phase inverter, and I cannot find the formula everywhere...

I am equally interested in both topics, but I am having trouble making up my mind as to which one to pick. Anyone here wish they did one or picked the other? Future prospects? I like MechE topics such as thermodynamics, FEA, CFD, materials etc, but I also like ElecE topics such as...

What type of technique would allow you to visualize the nerve electrical signal of the brain? Is it possible to do that with MRI?