Electricity Definition and 999 Threads

There are various methods to slow and even stop visible light. Most of these methods appear to be slowing the group velocity of light, not the phase velocity. Can you slow the velocity of propagation of electricity? I have seen estimates that electricity, in a wire, propagates at 2/3 the...

Hello all, I am an engineering student currently undertaking a project at univeristy. It involves the sorting of 4 different balls of which I have deduced how to sort 2 of them leaving just 2 types of balls to sort... The remaining two are of identical size, 10mm in radius, and are...

I was wondering if I may interprete AC current as a tranverse wave trough copper as medium. So this wave behaviour has a general wave-form written as: \zeta(x,t)=\zeta_{0}sin(kx-\omega.t) This is a solution to the partial differential equation: \frac{\partial^{2}\zeta}{\partial...

Homework Statement If you step up the voltage in a wire by a factor of 100, how is heat affected? A. No change B. Heat loss increases by a factor of 10000 C. Heat loss decreases by a factor of 10000 D. Not enough information to tell Answer: "C, heat loss decreases by a factor of 10000...

Salt water and tap water conducting electricity - help appreciated :) Hello, Thanks in advance for helping me with my question! I'm so excited to find this physics forum of such talented people. My question is, I know that salt water conducts electricity more than tap water due to the ions...

Homework Statement A coal-fired steam power plant operates on the ideal Rankine cycle. Feedwater from the condenser at P1 = 10 kPa is pumped to the boiler at P2 = P3 = 20 MPa, where it is superheated and exits the boiler at T3 = 550 °C. The moisture content in the turbine is...

What's the part called that converts spinning, rotor, motor power into electricity? If I were to buy one what would I call it? Regards, David

Let's say I have a magnet inside a coil of wire. If I spin the magnet for a 10 second period, twice, the second time spinning it significantly faster, will more current be induced during the second period? And would this apply to generators in wind turbines, etc.? Thanks.

Does Electron spin generate electricity? I know that with the electron spin generates a magnetic field, but does it generate an electricity? Thanks for any input!

i am in total confusion to co-relate p.d of electrostatic and p.d of electricity. can somebody help me out?/

I don't really understand the concept of what makes work positive or negative for example if 3 charges are brought together from infinite what is the work done on them? I am extremely confused about what make work positive and negative.

I originally wanted to post this in the EE forum, but after seeing the sticky there, I decided that this might be a better place. 1. I got the whole thing about unit conversions (like from V to kV, move the decimal point 3 to the left -- the number becomes smaller by 10^3). Right now, we're...

to be more specific how can you make electricity by spinning a mechanism?

In which direction did your physics text teach electricity flows? Please mention the country in which the school where you learned this was located. I think there may be differences based on location in the world.

Elevator design -no electricity supply? I hope someone can help me. I'm designing a building for uni that requires several lifts (elevators) which transfer bicycles and pallets vertically. My tutor suggested to look at energy efficient lifts. He mentioned that he had seen a lift, which...

OK is it true that you can die if you are wet and are shocked by standard 120 volts? Like for example if you took a bath and stuck a fork could you die? btw I touched a 120 volt wire with a wet finger, but it wasn't too bad/fatal... (is it more likely to die or survive if wet?)

what is electricity? For a long time i thought that electricity was just electron moving in a coil from negative to positive terminals. and that's what my teachers have taught me too... But i recently stumbled upon something called electricity through induction which has led me to doubt the...

Homework Statement Two points charges A(+10. uC) and b(+40.0 uC) are placed .2 m apart forming line ab. Calculate the force experienced by a point charge C(+10.0 uC) placed on line Ab, .06 m from A Homework Equations F=kq1q2/d^2 The Attempt at a Solution First I tried making a diagram...

I was checking my syllabus to see if my coursebook was missing out on any of the syllabus statements, and it mostly isn't. But for this one statement the explanation in the book isn't good enough and I don't understand what it's trying to say. The chapter is Electric Fields, and the...

why does nobody do it on a large scale? There's countless videos on the net of people making 'tesla' machines out of simple components and doing things like, I don't know, charging their phone - without any cell. I would think it was codswallap if not for the fact that all the videos seem to...

Homework Statement What should happen to the electrons in a insulated metal object when a negatively charged plastic rod is brought near the insulated metal The Attempt at a Solution I thought the electrons will repel each other and the insulated object will move away from the rod...

Homework Statement I have a few problems that I found in my review package that I just couldn't figure out. I've been trying all day as I'm used to the normal F=kqq/r^2. These are higher levelled problems, but my prof says that they will be on the midterm which is coming up next week. If...

My son brought home a fourth-grade science experiment a few days ago: He was to make some sort of property change in a steel nail. He had decided that he wanted to make it rust, so we set about creating an electrolyte solution out of salt and water and leaving it in there. There wasn't...

Does electricity travel through vacuum?If so ,is it a good conductor?What is its resistance.

I need to know because i need a chip that is a conductor and absorbs heat then converts it to electricity.

Homework Statement [attachment] Homework Equations I=V/R V=R*I R=V/I Rseries = R1 + R2 + R3 ... 1/Rparallel = 1/R1 + 1/R2 + 1/R3 ... Kirchhoff Law The Attempt at a Solution Rsource = Vsource/Isource Rsource = 50/0.25 Rsource = 200Ω I don't know what to do next!

I am going to use piezoelectric disks to generate energy from pedestrial movement on footpath please help me which circuit i have to prefer for my project?

Homework Statement Calculate the resistance of a strand of aluminium wire of diameter 4.0mm and length 1.0m, given its resistivity is 2.5*10^-8 Ωm. What would be the resistance per meter of 50 strands of this wire, using the strands in parallel as a cable?Homework Equations ∏d^2/4 for area...

Hey guys, Most physics or introductory electronics books that I have read begin the topic of electricity by introducing static electricity. The books introduce static electricity by either talking about the amber and the wool experiment or the glass rod and the silk cloth. My question is...

Imagine a pallet (or any other kind of small platform) tied to a cable or wire, which is itself attached to a turbine, all of this elevated a few meters above the ground. Now imagine a heavy ball or weight that falls on the pallet and pushes it down, thus pulling the cable down which activates...

How do I do any calculation when I want to know what kind of a dynamo I need to connect to my fitness bike to produce electricity? And then, what kind of batteries?

In an experiment to demonstarte relationship between current and p.d. in an electrilyte the book says to plot current on the Y axis. Why is this? V = IR R = V/I I always assumed when you plot graphs, the slope must equal the constant. Any input appreciated.

Hi there, I am currently attempting to teach AS level electiricity but am finding it really hard understanding some of the aspects of it myself, let alone teach the kids it! They are really struggling with the concepts of voltage, current, resistance and charge, especially how they all link...

Hi All :) Im working on a small contraption and I need to create a power source from random movement. I herd there are some liquids that can be mixed together to have high electrical output generated. or maybe liquid and gas? Either way it must be safe and non toxic. thank you for your time...

I don't quite understand this concept, i know that electricity is the motion of electrons through a conductor. what exactly is the potential difference between two points in a conductor? Is it similar to the Bernoulli's principle where the air flows from high pressure to low pressure area...

Hopefully this question hasn't been asked here before, I did a search and it seems everyone else is asking much more practical questions. Anyway...The Situation: I'm modifying a Nerf gun (this one for anyone who's curious)...

My textbook says electrolytes conduct electricity by the Movement of positive and negative ions. I have always thought it was due to the movement Of free electrons but it isn't so . Why is this so ? I have visited a few websites but am unable to reach an answer . By the way, when we say ionic...

These are some questions which my teacher told us would likely be on a test tomorrow. I'd just like to know the best possible answers for them, as I have a general idea but I'd like to be sure. 1. Why are loads connected in a household in parallel rather than series? 2. Why must...

A proton (m = 1.7 * 10–27 kg, q = +1.6 * 10–19 C) starts from rest at point A and has a speed of 40 km/s at point B. Only electric forces act on it during this motion. Determine the electric potential difference VB-VA. Here is what I did: V = \frac{U}{q} U = qV = \frac{1}{2}mv^2 V_B - V_A...

You probably know how to bend water: Use a comb and rub it with wool (or just comb your hair) and hold it next to thin jet of water coming out of a tap. Here is a video: Comb with wool An explanation is offered here (the water molecule is polar). However, I remember my physics teacher...

What do you guys think is the best way to produce electricity(fossil fuel, solar, wind, etc...)? Explain why.

I have just created a short animated video explaining all the concepts of electromagnetism. It is at: http://youtu.be/XiHVe8U5PhU I put a lot of of time and effort into making the animations, so please take a look at this, and please pass it along to anyone who you think might be...

My question is how do I find the voltage across a capacitor? I have an RLC circuit with a switch and battery. It only gives me the values for the battery, L, C, and R. My main question is, is there an equation or something to find the voltage across a capacitor?

Hey guys, I have this 8 page research paper coming up. I decided to write about what electricity is, how it is created, and how does it power tools. My professor said it was too general so could you guys give me a specific topic related to electricity? Something do-able in 8 pages. Not too...

I am interested in generating heat manually by rubbing two materials together. I am trying to find the most efficient way to generate the most heat. I've read a little about thermoelectricity where if a current flows in a circuit consisting of two different conductors then one of the junctions...

Hi guys, I'm studying as an Electrical Engineer and I have very little knowledge in this subject. Please explain to me what electricity is, how it is created, and how does it work to power electronics and stuff(be as descriptive as you can). ..and also, if you don't mind, please give a...

Please help! Also, please correct any misunderstandings which I have. I have read about electricity basics and what happens on the atomic level until I have read ideas which compete with each other. 1 - I've read that the word electricity applies to particles with a negative charge (more...

Hi, I am in processing of sizing a generator that biomass as fuel to be fed back to the grid as part of feed in tariff initiatives. However, I would like to know roughly how this feeding mechanism works. For example, in a workshop, a machine motor would initially draw up to 5X the rated motor...

[PLAIN]https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/313028_10150383340891940_666206939_8328916_99129355_n.jpg Would this system work, if the air-water isolation problem (water leakage into the air tank) is solved? If it would work, where does the input energy comes from? We obtain...

Hi Experts, May I know what is stopping cars from converting exhaust heat to electricity? Eg. using : 1. Thermo-electric generator TEG. 2. steam turbine Just curious to know why this energy is not tapped. Thanks. regards Ramone