Electricity Definition and 999 Threads

Homework Statement If lightning strikes a tree such that there is the same current through it as there was through the lightning conductor, then a much larger potential difference exists between top and bottom of the tree. Explain why this is so. The Attempt at a Solution Is this...

Since the instructor of my course doesn't use a textbook and just teaches based off his notes, what would be a good text to supplement my learning (when asked what he recomends, he just said find something in the library). Does electrodynamics = electricty and magnetism? I've heard this one is...

How do you calculate cost per unit of electricity over a certain time that a generator produces?

I am going into my fall semester of E&M and am trying to decide upon a topic to write about for an honors project. I have not taken an E&M course yet so it is difficult for me to really find which topics are too advanced scientifically or mathematically at this point. So far I have taken a...

Hello. I’m a new addition to the board, and if I’ve posted in the wrong place or this is otherwise unwelcome, please PM me and let me know. I’m a writer and I’m working on a science-fiction novel set on Mars in the distant future. I can gather most of the information on the planet, the...

Hello all! I was recently watching a documentary which delved into the theory (is it a theory?) that quantum particles can be in two places at once; indeed, millions of places at once. I've heard this all before, but the one thing that I picked up on this time was that when a particle is...

I want to know if the flow of electron act like a domino effect where 1 electron enter 1 atom than 1 extra electron of that atom is ejected and so on or is it the same electron that move from where the current is produce to your home.

Hello PF, I am a few weeks from starting my second year as an undergraduate. This fall I will be taking the Electricity and Magnetism course for physics majors (crosslisted for graduate students). Last spring I took the introductory physics course on electrostatics and magnetostatics. The...

Homework Statement Find the resistance between the A and B( image attached)Homework Equations The Attempt at a Solution I could only simplify the diagram to this (2 attached pic) and i can't proceed any further since i can't identy find any parallel or series circuit/

http://img404.imageshack.us/img404/9523/dynamos.jpg I understand that when the rotating magnet spins, current should be induced in the coils which powers the lights. So what is the point of the soft iron core? The rotating magnet should magnetise it because it is near it, and it should...

I don't care to understand how to measure it, just want to understand how it works. First help me understand how a basic rechargeable fluid battery system works. Please understand i have an 8th grade education, a ged, and some tech school. I had to teach myself alot. How i understand it...

I am trying to calculate the output voltage for 1 coil in an axial generator/altenator I have 2 magnets with Br Max 13200 Gauss on opposing sides of the rotor (N-S facing), The coil is between them on stator. Using faradays equations what is the effective Br (Gauss/Tesla) that should be used...

Modern high voltage electrical transmission lines (400kV) may be constructed with cable having a core of twisted steel strands surrounded by layers of twisted aluminium strands? What advantage is gained by using strands of steel rather than a single wire of equivalent total cross section?

When breaking down a molecule using electricity, what determines how much of the substance is broken down per second. Is it the voltage, current, or something else I'm not thinking of?

hi , i wanted to ask why does current in a wire produces a magnetic field ? and can anyone explain how maxwell related electricity and magnetism , easily (im in high school)

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HI! i only know about the basics of current and electricity , but, i wanted to ask this.. the drift velocity in electrons is approx 10^-4 and thermal velocity is 10^6 m/s , which is not very large compared to the length of wires connecting power stations and homes , but still we get...

A 1000-turn toroidal solenoid has a central radius of 4.2 cm and is carrying a current of 1.7 A. What is the magnitude of the magnetic field inside the solenoid at the central radius? (μ0=4∏×10^-7 T ∙ m/A) r= 4.2cm= 0.042m B=(μ0)(I)/(2∏)(r) ⇔ (4∏×10^-7)(1.7)/(2∏)(0.042) ⇔ 1.43x10^-8 T? Or...

If the area of a tube is 0.0000283 m, with moving ions contributing to a magnetic field of 44.0x10^-4 T. What is the current flowing through the tube? [permeability of free space 'mu subzero'= 4∏x10^-4]. I don't have a clue of how to start attacking this problem, have a genius professor, but...

So from my understanding of glow sticks, the decomposition of hydrogen peroxide provides electrons that excites the fluorescent dye and gives off that classical glow-stick light source. My question is, could one put a DC current over the solution and still theoretically obtain the same...

I was wondering for quite a while what would happen if you exposed a living organism to electricity of ~250.000 Ampère at 1.000.000 Volts (I'm unsure if the values given are insanely high or not). Would the organism just end up "everywhere" or something else??

Hi to all physicists How can convert muscular (mechanical) energy to electricity without using a generator? In fact I am looking for a way to convert muscular energy to electricity energy without use the generator.

By means of an antenna circuit tuned to 7.8hz (earth's resonant frequency). Orrrr an Earth battery? I'm not quite sure how those work exactly but can they be tuned? Edit: Earth battery (or Earth Return) was something discovered by Alexander Bain, he got about 1 volt from the ground by placing 2...

I'm trying to understand why static discharge (or just plain high voltage) damages semiconductors, in particular integrated circuits. What happens when a chip gets hit by a voltage spike that it can't handle?

Hi everyone! I need your help to design an antenna which produces current. Since i m not an engineer & have no technical knowledge. So, here is the principle! Guid me how to design an antenna for radio waves or any other one which will produce a maximum attainable current from these by...

Some background: This was a quiz I recently had in which I lost a few points for missing an "x & y component" for one of the directions. My thinking is that because the problem was not actually set up with a specified order of charges there are a few different answers you could get. I intend...

No, you didn't read the title wrong. I am really self studying a physics class. I just finished Mechanics (Physics I) and since I want to go to college to study physics to become an engineer or physicist. I need to take the next class, E&M (Physics II, Electricity and Magnetism). However, I...

After some of the information I've read and a few youtube videos, this is a rough idea of how I view a basic internet structure. However, I would like to find out how money changes hands in this industry. This is my guesstimate of who pays who: The individual residential households pay the...

Throughout the journey of an aeroplane flight, the magnetic field of the Earth will induce and electro motive force in the wings. Is it possible to generate electricty from this EMF? Also I am wondering when to use sin or cos.. for the formula phi = BA

Homework Statement A 240 W television operates for 4.0 h a day in a typical Canadian home. Calculate the resistance of the television. Homework Equations 1) I = Q/∆ t 2) E = QxV 3) P = (Q x V)/ ∆t 4) P = I^2 x R 5) P = V^2/R 6) P = I x V 7) V = W/Q...

Homework Statement Initially, metal sphere X is charged to an electric potential of 10,000 volts, with a total charge on its surface of +Q. Metal spheres Y and Z are initially uncharged. Spheres Y and Z are the same size as sphere X. All three spheres are held by insulated stands. 6...

What does static mean ? Why is a positive charge attracted to a negative charge ? What makes them attractive ?

I have 2 questions. I have been thinking about these two things a while, and got no one to ask, so hope to get some info/answeres here:) 1: When an electron is standing still, it produces an electric field (and no magnetic field), right? So when many electrons is moving with a constant...

I was just wondering how static electricity has a high voltage. Is it because of the difference of charge between the two objects e.g you and the ground? Or is it due to the electric field which surrounds an static charged object, so the electric field cause ions to build in the air allowing...

I have this idea about creating a 10 meter plastic/metal pipe that would go from a house roof to the ground and having a "U' shape close to the ground so that both holes are directed at the sky. Does anyone have a clue if the difference in atmospheirc pressure between both holes (10 meters...

Does the force of magnetism cause electricity?

supposedly there is abundant electricity to be harnessed from converting static electricity in the atmosphere to the power grid (yeah right) http://sefelectric.com/ trying to convince someone that this is just a pump and dump scheme (its a penny stock & the company has a $100M valuation &...

I've been able to do all the calculations and whatnot well in my physics class, but I recently stopped to think more about the concept of electricity and how it fundamentally works, but quite frankly I'm a bit stumped and there are some gaping holes in my understanding. Would someone please be...

Hi, I am new to things involving electricity and electricity generation, and I have a question that I can't find an answer to and I was hoping that someone here might be able to help me. I would like to perform an experiment but I need some help before buying the items needed. I would like...

If we would build a copper ring that would orbit around the Earth (like a big belt), could we generate electricity from it (because of the Earth's magnetic field). I know it's impractical, but I'm curious as to how much electricity we could get.

With all but one of the Japanese nuclear plants offline (and the last one due to shut down in early May), how are the utilities continuing to meet demand? I read in various places statements such as "Japan has been importing unprecedented amounts of coal, oil and natural gas, resulting in...

I was studying the cathode ray experiment on how electron was discovered and the experiment uses battery for voltage. How did the people invent battery without knowing electrons and protons ( by chance?) And how was the name cathode and anode given without knowing which is positive and...

The hydro meter for my house sits on a pole at the front of my property (5.5 acres) approximetly 200 - 250ft from my house I can't give you the wire size that runs under ground. My question is: Is there a loss of power in the distance from the meter to the house and would this result in my...

Homework Statement A metallic wire has a diameter of 4.12mm. When the current in the wire is 8.00 A, the drift velocity is 5.40 10^-5 m/s What is the density of free electrons in the metal? Express your answer numerically in m^-3 to two significant figures. Homework Equations I=nqv(drift)a...

Guess its pretty simple- Case1- I connect a bulb of less power to a battery of voltage, say 1.5volts. Case2- I connect a bulb of more power to another battery of same voltage, say 1.5volts. What is difference seen in the two cases? : • will the battery drainout quicker in case2...

Homework Statement (i) What is the strength and direction of the force per unit length acting on a straight conductor carrying an electrical current, I, in a magnetic field, B? (ii) The figure below shows a square frame of aluminium set at an angle θ to the direction of a strong static...

Hello, I have recently started learning about electricity and electronics and would like to have a few things explained. I apologize if these questions are not up to your standards, as this is a serious board. If a watt is amperes times volts let's say you have 3600 watts available at home...

if electricity is flow of electrons and also positive and negative charges attract then why electricity needs a conducting medium. electrons has mass and it should just travel through vaccum then why in vacuum electricity cann't travel please reply!

Homework Statement Suppose you have two isolated conducting spheres that are both neutral. You move 2mC of charge from one to the other. a. What is the charge now on each sphere? My solution: One sphere is positively charged with 2mC more protons, while the other is negatively charged with...

i got it until ' R P(1) = 3 ohm ' but shouldn't the effective resistance of arm ADE be 6+3=9 and effect. resistance b/w A & E be (9*6) / 9+6 = 54/15 ?