Electricity Definition and 999 Threads

Can anyone please explain what is drift velocity. I was absent for that class. I need a detailed explanation and derivation of that. Please help.

I know very little about electricity, but I'm trying to understand it better. I'm trying to wrap my head around something- I have heard it said that, "the flow of electricity through a circuit is due to the movement of electrons". While this explanation sounds simple enough, I have some...

What do you call Generation of electricity using waste heat from processes to make steam and drive generators

I'm a mechatronics engineering student, and I know that electronics is a requirement in most engineering programs. I'm been dealing with electronics recently and I've been studying electric circuits. I've been noticing that in some of them instead of being closed (in diagrams) they are like...

Hi, I'm having a difficult time understanding how voltage is reduced in a circuit. I know the relationship of V= IR, but I still don't understand. I think part of the reason I do not understand is the wording used, and the other part is from experience. For example if I have a fan that only...

Gruxg has posted a thread on November 4, 2012, titled as "If you touch a live wire without touching the ground, do you get an electric shock?". I think that this thread would deserve more consideration as it discusses an essential subject but unfortunately it is closed for further replies, so I...

Homework Statement Homework Equations V=IR Kirchoffs Current Law The Attempt at a Solution I picked the middle node (the one surrounded by 3 resistors) as my reference. V1 and V2 are my other two nodes. I'm also assuming that V1>V2, V1<reference Using Kirchoffs Current Law: (Node 1)...

Homework Statement Dry air has a resistivity of about 3*10^13 Ωm. A capacitor has square plates 10cm on a side separated by 1.2mm of dry air. The capacitor is charged to 250V. Assuming the potential difference does not change as the charge flows, what fraction of the charge will flow across the...

My textbook says "the net flux is zero through a closed surface that does not contain any net charge," and justifies it by saying that everything flowing in has an equal thing flowing out. This makes ABSOLUTELY NO sense to me.

Homework Statement Ina light bulb, billions of electrons flow through the tungsten wire bumping around, causing the filament to glow hot. Hot tungsten evaporates slowly, so its initial thickness profile r(x, t=0) can change over time. Consider a volume V of tungsten, with N bonds total, each...

Homework Statement Hello, we have built a system in which energy is harvested through the use of an oscillating fin, this energy is stored within a flywheel which operates at a frequency f, we are then connecting this flywheel, via a smaller gear (gear ratio = 10) to an induction motor which...

Im doing a project on school. I want to re-use energy. I know that it will not run forever (but i hope it runs very long). So i wanted to ask if the image below is right and i could use it at school. If it shouldn´t work please say what i can make better. Thanks for your Help! Here is my image...

Greetings !New to the forums. Here expanding my concept of what AC Electricity is My question (correct me if wrong).. If AC power alternates between +,- at a rate of 60Hertz/second and negative is used as -earth- at the AC generator If the hot wire touches the ground would happen? (I think...

Homework Statement The electric field strength is 2.50×104 N/C inside a parallel-plate capacitor with a 1.20 mm spacing. An electron is released from rest at the negative plate. What is the electron's speed when it reaches the positive plate? Homework Equations F = eE = ma vf2 = vi2 + 2ad...

In the charged rod experiment, why didn't my hand neutralize the charge formed in the rod, since my body is a conductor and it is connected to the Earth?

Homework Statement Homework Equations For R, current I=E/R and for X, I=E/X... both are separate cases. The Attempt at a Solution [/B] Why does the balancing change? The potential difference across each resistor is E Itself right? I tried by assuming an arbitary internal resistance r...

I'm doing a quality of measurements coursework at the moment, the coursework was to find the efficiency of a kettle, and to do this, one of the factors that I needed to find was the voltage. So in 300ml of water, the voltage was 240.5V 400ml - 244V 500ml - 243V 600ml - 245V 700ml - 241.4V...

Homework Statement Consider an infinitely long solid cylinder of uniform linear charge density λ1 and radius a inside a hollow cylindrical pipe of inner radius b and outer radius c and uniform linear charge density λ2. A cross-sectional view of the system is shown below(linked and attached)...

I need help. I am installing new networked alarm panels throughout a building. There is a room where one panel is and that panel is continually having components fail. While in this room it is also very common for me to receive a static shock when coming in contact with any metal. I realize...

Can we use a mirror to reflect sun's light on a solar panel and generate electricity?

People say that the voltage across one resistor is equal to the voltage supplied. I've drawn a picture of a simple circuit with two points near the positive terminal. Apparently, if we take the potential difference of these two points, it will equal 9V according to the above saying (which can...

This is a concept that has long since plagued me. I will quote an article off of Google about the concept I am confused about: "Consider a collection of static point charges located at position vectors (where runs from 1 to ). What is the electrostatic energy stored in such a collection...

So I'm having trouble visualizing how voltage drops more within different parts of a circuit, such as a resistor vs. wire. I know all the general equations but the concept is hard for me to comprehend and I am stuck on one notion. So, say you have a simple DC circuit with just a resistor and...

So I am trying to understand how a ULTC operates in the Reactive Power Control mode (it adjusts taps to control the reactive power in a line). What equation is governing it's operation, and what variables does it adjust in order to increase/decrease reactive flow? Is it just the simple reactive...

So basically, I am inferring the following based off of what I've learned. When we hook a battery up to a circuit, this creates a potential difference. Say we use a 9V battery. Here is a picture: From what I know, the horizontal is a equipotential surface, and the vertical has different...

HI everyone. I'm an engineering strudent, looking for online material with exercises on diodes...anyone can send me a link here with explanations of the various exercises? Thank you very much :)

If we can create a magnetic field with a solenoid, why can not we generate electricity with magnets?

(1) I previously learned that a constant magnetic field causes a force on any electrons within its range. Clearly, this force would cause electrons to move. Isn't this creating a current? (2) However, now apparently I am told that the only varying magnetic fields can create a current. I.e...

How exactly do the electrons move from the capacitor to the rest of the circuit? Do they fly between the capacitors plates, or can they only travel where there is a wire connection? (I.e., if a small chunk of our circuit looks like this: A-------| |-------B can an electron start from A, go to...

Suppose we have a circuit with two capacitors connected to each other, C1 and C2. C1 is charged and has a potential difference of 5 V (V1=5V), but C2 is not charged (V2=0) Apparently it is known that the potential difference of these two capacitors will want to reach equilibrium. So V1=V2...

Homework Statement What amount of heat will be generated in a coil of resistance R due to a charge q passing through it if the current in the coil decreases down to zero uniformly during a time interval ##\Delta t## Homework Equations ##dH=i^2Rdt## ##i=\frac{dq}{dt}## The Attempt at a...

Hello, Does anyone shield themselves from computer / monitor from EMF radiation? if so what materials do you use to cover/coat your electronics? I am buying an EMF meter soon (Trifield 100XE) and plan on solving all my EMF issues, specifically around my computer tower, monitor, and other...

Homework Statement A point charge q =+6.4 \mu \mathrm{C} is placed at each corner of an equilateral triangle with sides 0.29 \mathrm{m} in length. What is the magnitude of the electric field at the midpoint of any of the three sides of the triangle? Hint: if you are careful to examine the...

Homework Statement Homework Equations P = V^2 / R 1/Rt = sum(1/Ri) (parallel) The Attempt at a Solution [/B] Since all the answer choices express the solution in terms of V^2 / R, I tried to find the voltage drop across resistor #2 to find the power. I collapsed the two parallel...

Homework Statement If Q1 in the above figure is twice Q2 and both are positive, where can a point of zero potential be found?Homework Equations V = kq/r The Attempt at a Solution I know that eventually I'll have to set it up so that kq/r = kq/r, but my problem is, how do you know where this...

Homework Statement [/B] In the above figure, if Q1 and Q2 are positive, where could a negative charge be placed and have a vertically upward net force on it? Homework Equations F = k|q||q| / (r^2) The Attempt at a Solution I wrote the force equations for the negative charge and both positive...

http://prntscr.com/60xcwx Thank you

Homework Statement Ignore the internal resistance of the battery and assume it is merely a battery. Calculate the equivalent resistance of the circuit. Homework Equations 1/Req = 1/R + 1/R ... (parallel) Req = R + R ... (series) The Attempt at a Solution I know this is fairly simple but I...

Homework Statement The figure gives the electric potential V(x) along a copper wire carrying uniform current, from a point of higher potential Vs = 9.00 μV at x = 0 to a point of zero potential at xs = 3.20 m. The wire has a radius of 1.50 mm, and copper has a resistivity of 1.69 × 10-8 Ω·m...

Homework Statement Capacitor 3 in Figure (a) is a variable capacitor (its capacitance C3 can be varied). Figure (b) gives the electric potential V1 across capacitor 1 versus C3. The horizontal scale is set by C3s = 20 μF. Electric potential V1 approaches an asymptote of 10 V as C3 approaches...

Homework Statement [/B] Consider the circuit above. You are given the following measured values: V = 1.5 V R1 = 100 R2 = 100 R3 = 50 R4 = 50 R5 = 50 Homework Equations Kirchhoff's Loop Rule and Junction Rule The Attempt at a Solution I tried setting this up using the junction and loop...

I have several questions about poles and towers. a. Does all of transmission towers carries three-phase powers? Is there no transmission towers designated for single-phase? b. Does all towers are for transmission purposes only? Is there any towers in the world used for distribution instead of...

In my textbook it says that work done by a nonconservative force (an applied force) has the same sign as the change of potential energy? For instance, if I push a positive test charge from an infinite distance away to a negative charge, then the test charge goes from high potential energy to...

Hi everyone. On these days, by watching solar panels and similar stuff, I just thought about it, and why they take such a wide surface to produce energy, and why their output is often low, as we all know. By navigating here on the internet, I've just seen a device called OPO (Optical...

A small thermocouple would produce tiny amounts of electricity as temperature unevenly fluctuates. But if I tried to store that energy using a diode and capacitor, I would guess that the tiny reverse current flow through the diode would be enough to not allow for such a self charging system to...

Hello, I want to create a motion using electricity, using the cheapest means possible (DIY). Basically I'm trying to rotate an object 90degrees when the current is on, and back to its original position when the current is off. The questions are: 1) Is this possible? 2) Can this be done using...

Electrons are moving in moves in all sorts of directions, causing the net electric charge to cancel out. But, when you apply a voltage, there's a small amount of electrons that will move towards the direction in the direction of the voltage. This is called the drift speed. Am I right? I read...

In the direct current circuit, when you have a switch and you turn it on, you get the coil to generate a current to the opposite direction but the magnitude isn't big enough to offset the main one. But in the case of alternating currents, the coil seems to generate enough current up to the...

Hi everyone, I just came across an exercise that asks me to explain how I would measure the change of resistance of a metal wire between a temperature of 0º C and 100º C. The answer to the question is below, what I don't understand is why is there a need to put ice in the water bath and the need...

Pardon me if I stated the title incorrectly/ informally. I just want to say about the title is about the 220 V, 60 Hz source (present in our outlets also) in our house by which comes from nearby electrical post. I have four questions in this post/thread so kindly tell me if I need to edit this...