Electricity Definition and 999 Threads

this is like 1800s technology for most parts

Hi, I'm new to this forum so please don't get mad if this post is in the wrong place. I have a laser beam pointed at a solar panel (regular PV cells) and the current comes out as expected on my oscilloscope (small waves varying like pulses between 0.45 and 0.50 V regularly). I tried...

Hi I’m trying to estimate how much electricity a new high speed train in the UK would use to go at 400 km/h and how many wind turbines it would require to run it. My physics is a bit rusty so I’d appreciate it if someone would check my calculations. It is difficult to estimate how much...

Homework Statement What is the Kinetic Energy of an electron that passes undeviated through perpendicular electric and magnetic fields if E = 4.0 kV/m and B = 8.0 mT? m_{e} = 9.1 \times 10^{-31} \textup{kg} q_{e} = 1.6 \times 10^{-19} \textup{C} Homework Equations I got stuck doing...

w = x = y = z , If this were a pump system with water, I think the pressure and flow would be much higher at reading #2, because water has momentum? What about electricity, would the current be higher at #2?

Homework Statement A voltage of a car battery is 12V, the current requires for movement is 200A. When we turn the lights on the voltage drops to 11.1V. The power of each backlight is 55 watt, the power of each front light is 12 watt. A) Calculate the internal resistance of the battery...

Homework Statement Take the Earth for instance, if I were to draw field lines, would it be field lines coming out of the mass or into the mass? I initially thought it would be going out because we could look at it as a "positive charge", but then I thought that was silly because gravity is...

Ok so I understand how a voltage source works, with electrons flowing from a high potential to a low potential. But I'm a little confused about solar cells. So the way they work is that an incoming photon strikes an electron and gives it enough energy to break free and create a current. But...

We were given holiday homework from our teacher, but I'm not sure if we were given the proper tools to solve it. Is it only a formulas game? If so, how close am I to not being embarrassingly wrong? Homework Statement An electrical engine that requires a flow of 5 A with the useful power...

Hi, Originally I had a question about a wire that allows electrons to move to higher voltage. I could not figure out why the wire does not lose electrons to the point it runs out. The question was answered on these forums when someone mentioned salt bridges, which lead me to watch some video...

Nikola Tesla observed that electrons transmitted through a near perfect vacuum in his vacuum tubes appeared as corona several feet through the air surrounding the tube. He thought that if there is nothing in the tube between the electrode and the glass then how do the electrons convey through...

I've always been given conflicting messages like that we only use conventional current because they were confused years and years ago. Anyway I'm wondering if 'electricity' is the flow of electrons or "electric charge" like I heard once, I assume they meant like a flow of empty valency shell...

I think I remember reading somewhere that almost every moment of our lives we are surrounded by thousands of volts of ambient static electricity caused by the movement of air and clouds, it's just that we don't notice it. I may have mixed up my information so I'm just asking for clarification...

Homework Statement A 19-cm-long nichrome wire is connected across the terminals of a 1.8 V battery. If the current in the wire is 2.1 A, what is the wire's diameter in mm? Homework Equations R = Rho*L -------- A v=ir The Attempt at a Solution rho for this = 100...

http://www.nuenergy.org/pdf/static-electricity-converter.pdf

You have a positively charged rod and you have a neutral metal sphere hanging on a wire. If the positively charged rod approaches the sphere, the sphere will be repulsed - correct?

Hi, The UK., electricity supply is 13 amps at 230 volts. With such a current and e.m.f., how can we run appliances which don't need that e.g., a hairdryer with a 3 amp fuse. What stops the full 13 amps overwhelming the appliance? My question is not well put but I'm sure you know what I'm...

I need help understanding this conceptually, so can anybody please correct me and help me understand this? If I'm correct then just say so.Diagram: http://i324.photobucket.com/albums/k327/ProtoGirlEXE/labVpic3.jpg the circles are bulbsOk so the basically in an open circuit there is no flow and...

Hello, I am preparing a material about static electricity, and it's basically finished. However, I have a question what puzzles me. I hope people in this forum can fill that in. So, the core process is that electrons hate to float in the insulators, so they hang on the surface of those...

Current electricity... Homework Statement In the circuit shown(please refer to attchment) only thing missing is that the battery has an internal resistance of r. Now When key K1 is closed the ammeter reads I0 whether K2 is open or closed. But when K1 is open the ammter reads I0 /2 when K2 is...

Homework Statement Please refer to the diagram(attachment)...the circuit contains two resistors in series of 25 and 15 ohm respectively and there are two batteries of emf 10 V and 5 V respectively ...Only thing missing in the diagram is that both the batteries have internal resistances of 2.5...

I think what I am doing is pertaining to ohms law but I'm not sure because we're not suppose to rely on equations or literal physics terms, but when we learned from previous labs. So this is mostly conceptual and I want to make sure I'm thinking through this correctly. Diagram 1...

How is static electricity charge distributed over the human body if skin (1100 - 496,000 ohms) is a good insulator? For example, if one wears rubber-soled shoes and walks around on a rug, the shoes will obtain a negative charge. Then, if one touches a doorknob or some other metal object, a spark...

As an assignment i need to figure out the most efficient way to convert heat to electricity and so i searched through the internet and came across Prof. Hagelstein's work which is called semiconductor technology. In short, the technology is based on the principle of thermionics by replacing a...

Homework Statement Refer figure Note: ~ stands for proportionality sign and p stands for resistivity. The Attempt at a Solution R=pl/A Rnet~l2/A V is constant across each conductor, so magnitude of electric field must be constant for every case. Since drift velocity depends on electric...

I have a few questions. Which word came first, electricity or electron? I just learned that the electron was "discovered" in 1897. That's significantly after electricity had been "harnessed" for practical use. What did contemporary scientists/science books say electricity was?

I just read the following innocent sounding statement, which got me thinking: "An electron in motion relative to an observer generates a magnetic field..." This implies that, for an observer moving alongside at the same speed as the electron, there is no magnetic field. I understand the...

Hey all. I'm trying to find more info on converting moving ions into electricity. AKA Direct Energy Conversion. Anyone know any good sources? I don't really understand how they do it yet, even after reading a few things I found on google.

Hi I reside in India and last month , our electricity bill was Rs 510 for 163 kW-h Converting to US dollars, it is US$ 23021 at current exchange rates. So the rate is $ 141.24 / kW-h . I want to know what is the cost of electricity around the world for 1 kW-h.

Homework Statement 7. Find V1, V2, V3, I0, I1, I2, and I3 for the circuit in Figure 2. V0 = 120V R3=15 ohms R1=3 ohms R2 = 6 ohmsHomework Equations Kirchoff's law Ohm's law The Attempt at a SolutionR0 = R1 + R3 = 3 + 15 =18 ohms...

Homework Statement An equilateral triangle has sides of 0.11 m. Charges of -8.6, +8.0, and +1.5 µC are located at the corners of the triangle. Find the magnitude of the net electrostatic force exerted on the 1.5-µC charge. Homework Equations kqQ/d^2 The Attempt at a Solution first...

PLEASE help me by telling me if the following is true (below, when I say going with the flow I mean following the direction of electric field, and when I saw going against flow I mean going in opposite direction of electric field) Positive charges go with the flow Negative charges go against...

Can electricity be transmitted using Concentrated beams without using wires with no energy lost in the process?

Homework Statement Three resistors, 21, 43, and 73 , are connected in series, and a 0.55 A current passes through them. What is (a) the equivalent resistance and (b) the potential difference across the three resistors? Homework Equations i tried to use EPE/q by putting the equivalent...

ELECTRICITY GENERATION THROUGH THE CONVERSION OF ENERGY PRODUCED BY REVOLVING GEARS OF A TURNSTILE As the title implies, do you think it's feasible? I'm working on it as a topic on my research subject, but I'm having a hard time. I didn't know that there are lots of principles involved...

How much E&M is involved in a MechE degree? I'm a high school senior in AP Physics C: E&M and I hate it with a passion. I loved Mechanics, but E&M is terrible. Would I just need to take the one required class (Physics 2), or do I need to use multiple E&M concepts throughout undergrad? I am...

Homework Statement we wish to measure the resistance of a lit light bulb. Unfortunately, the resistance of the light bulb when hot is not the same as when it is cold. when the light bulb is turned on it becomes hot. we cannot easily measure the resistance of the light bulb when it is on (hot)...

I'm trying to replicate MIT's "Witricity", but on a smaller scale. I have a coil connected to a function generator and then a second coil (with more loops than the first) connected to an LED. So I guess now I have a transformer. And the LED lights up when the coils are up to 10cm apart. I...

Homework Statement Constants Given Colombs constant = 9 x 10^9 Charge of Proton = 1.6 x10^-19 Proton rest mass=1.673 x 10-27 Charge of electron = -1.6 x 10^-19 Electron Rest Mass = 9.11 x 10^-31 kg Homework Equations On the attachement The Attempt at a Solution On the...

Physics Grade 12 HELP! Electricity Unit I have attached the question paper with this post Homework Statement v=2 x 10 ^ 5 m/s Volatage=250 or 500? Constants Given: Coulombs constant = 9 x 10^9 Charge of proton/electron = 1.6 x 10^-19/-1.6 x 10^-19 Proton rest mass 1.673 x 10^-27 kg...

Is it physically conceivable the possibility of transmitting electricity between spatially separated objects (e.g. a few meters) in a wireless way?

I apologize, I wrote all of this out in a word processor before attempting to post it and I did not notice that there is a template for giving problems. I hope you forgive me, my posts tend to be wordy and take awhile to write; attempting to write it in the text box would result in the server...

If I have a really big charged object, is it possible to direct the charges to an object/the same place and generate current/electricity from it? It was just something I thought of, totally random, but I'd like to know the reasoning behind it C:

i was pondering over a few questions 1) if i were to connect a wire from the positive of a power source, and touch the other end to myself, would i get electrocuted? common sense tells me i will, but where is the close circuit? does electricity flow from source to me to the earth? and then...

Although I'm sure people have been looking to develop a solution like this since the beginning of time (at least, the first use of electricity), I'm trying to achieve a design that will enable perpetual electricity generation without the addition of conventional energy inputs. Essentially, I'm...

Homework Statement How would static electricity on your clothes or on your body affect an experiment involving charged objects? Homework Equations Coulomb's Law The Attempt at a Solution The static electricity would attract the objects due to the like charges, assuming the objects...

Static electricity in outer space? Somewhere I read that a space vehicle traveling in outer space picks up a static electricity charge. Is this true and if it is true, where does that static electric charge come from?

I came across a report entitled "Wind Farms Provide Negligible Useful Electricity" by Richard Courtney. You can google it its just available free on the internet. What I wanted to know, if anyone here works in the power grid industry, was it true or should it be taken with a pinch of salt...

Hi everyone. I want to heat a piece of Rubber by embedding copper strips or wires in it and passing electricity(120V - 2.5Amp) through it. The room temperature is 0(zero) deg Celsius and i want to heat the aluminum block(5" x 5" x 1") to 10 deg Celsius(Not more than 10 deg). Question...

Hello, I am a student making a generator. the main idea is to use the vibration with the magnet coil setting with the spring to generate electricity. I will use the permanent magnet, but i know that e = N w B A i decided to have a 12Volt output, constant vibration frequency in 100Hz the A...