Coil Definition and 906 Threads

I am looking for the B-field of a real coil. So a straight piece of pipe with some current density. Is it correct that there is no analytical solution to this? It would be enough if I had the field of a current rotating in a cylinder obviously. I am working on some Biot-Savart but either I...

I'm trying to build a Tesla coil, for the first time, and have some questions. Whatever sources i came across on the internet only tells how to build one out of household items, trash, radio shack components, etc, but not why and which way the thing works. The thing...

Homework Statement A square, single-turn wire coil L = 1.75 cm on a side is placed inside a solenoid that has a circular cross section of radius r = 2.82 cm. http://capa8.phy.ohiou.edu/res/ohiou/serwaylib/Graphics/Graph20/serw2014.gif The solenoid is 22.0 cm long and wound with 113 turns...

MMC capacitors exploding on my tesla coil, I need help! Im in a tight spot. I just recently built a decent sized tesla coil. Everything works flawlessly except that my capacitors are melting. They don't fail but they emit flames or they arc, (its hard to tell). Then after inspecting the...

Homework Statement Im currently in my last year of high school, and I'm writing a report on AC generators. I've heard a number of different things from different sources. When the coil is perpendicular to the magnetic field, maximum magnetic flux is flowing through the coil. This is then at a...

what does a self-resonant system mean?(e. g: a self-resonant coil )

Homework Statement A conducting coil of 1830 turns is connected to a galvanometer, and the total resistance of the circuit is 41.0 . The area of each turn is 4.70 10-4 m2. This coil is moved from a region where the magnetic field is zero into a region where it is nonzero, the normal to the...

I don't understand when you have an AC Circuit that has a coil, capacitor and resistance. What factor will the resonant frequency change when the frequency is tripled?

I had a small, about 1 foot secondary tall tesla coil with about 3 inch leaders coming off the toroid, and when i turned it on, I had an LED bike blinker light that would turn on when I would turn on the tesla coil. The blinker was about a foot away from the coil. I was wondering if anyone...

so, I'm pretty bored and decided that i want to make a speaker. I've bought some thick copper wire, and twisted it in the form of a coil, then twisted some more with a larger radius so i can put the first one inside the second one and so on.. my motivation to buy the thick wire was to maximize...

Homework Statement There is one square coil of area A that rotates with speed \omega around axis y. The magnetic field is uniform and points to the z direction. Show that the torque is \frac{A^2B^2N^2\omega sin\omega t}{R}. Homework Equations T = |\underline{m} \times \underline{B}|...

We have an infinite coil of N turns per unit length with radius a, carrying a current I and we want to find the magnetic field using Ampere's Law. If we put the loop outside the coil it can be established that B=0 If we use the loop to enclose the coil and we apply Ampere's Law we get that...

Homework Statement You have a coil of N turns, with current I through it. It is in a magnetic field B, which causes it to feel a torque. Give an expression for its magnetic dipole moment. Homework Equations The Attempt at a Solution Well, I know magnetic dipole moment is A...

I would like to calculate the natural frequency of a cantilevered spiral coil. So instead of having a standard beam which is straight, I have a beam which has one end fixed to an axle and the beam is spiralled several times around the axle. The end of the beam comes out of the spiral and runs...

I'm using PV cells to energize an air core coil. Is there a method in which I can determine the maximum length of 32 gauge magnetic wire to use, so that I don't use too few windings and burn the coil out or too many windings limiting its' potential. I'll be using 2 PV cells that are each rated...

Homework Statement http://img520.imageshack.us/img520/1843/picture7j.png Homework Equations for values 50 turn, 4.0 cm diameter, R = 0.50, surrounding 2.0 cm diameter, 20cm long, 200 turns, 60Hz through I_sol=(0.50A) sin(2πft) the solution would be...

Homework Statement You have a 1.10-m-long copper wire. You want to make an N-turn current loop that generates a 0.800 mT magnetic field at the center when the current is 1.50 A. You must use the entire wire. What will be the diameter of your coil? Homework Equations B =...

Hello all! I am a student of electrical & electronic engineering, in my final year; for my dissertation, I am exploring the possibility of scavenging energy from a magnetic field in order to power a wireless sensor..I am using a coil of rectangular cross section with a magnetic core occupying...

Hello everybody, First excuse me for my English. Could someone please explain how far the electromagnetic wave of a coil travels? Does it depend on the current flowing in the coil? The coil diameter? The coil's number of turns? What will happen to the waves if we increase the current of a...

Homework Statement Homework Equations e=d/dt(BAN) The Attempt at a Solution

What is the answer? Should be B Please Explain the reason behind I don't understand how an induced Magnetic Field will cause the coil to move. (Not Homework)Source:tycphysics.org/TIPERs/TIPER%206_20_02_keys%20pdf/EMI%205a_Key_6_02.pdf thanks for helping

Homework Statement At t=0, a rectangular coil of resistance R = 2 ohms and dimensions w = 3 cm and L = 8 cm enters a region of constant magnetic field B = 1.6 T directed into the screen as shown. The length of the region containing the magnetic field is LB = 15 cm. The coil is observed to...

Homework Statement When a wire carries an AC current with a known frequency you can use a Rogowski coil to determine the amplitude Imax of the current without disconnecting the wire to shunt the current in a meter. The Rogowski coil, shown in the figure, simply clips around the wire. It...

I'm currently making a coil assembly for a customer. The coil has the following specs: 120 VAC application 1,600 Turns 22 AWG magnet wire 12.5 ohms typically coil is in a circuit with a half sine wave rectifier and a solid state VAC controller current draw is .6 amps (72 watts)...

Homework Statement Suppose you wrap wire onto the core from a roll Nof cellophane tape to make a coil. Describe how you can use a bar magnet to produce an induced voltage in the coil. What is the order of magnitude of the emf you generate? State the quantities you take as data and their...

so i found a manual for a small HV device, using a flyback, powered by DC supply. here's the link for the http://tacashi.tripod.com/elctrncs/555sstc/555sstc.htm" i built a small platform giving the primary coil 8V in frequency which in theory should be around 20 KHz(i do not have an...

I have heard many things about electromagnetic induction, but I have got still more questions than answers. For example if a magnet is closing fast to a coil, a current will be induced in a coil. This also means, that part of the momentum will be given to those charged particles. If we count...

Find the mutual inductance (H) of the solenoid and coil shown below. The solenoid has 5263 turns per meter and an area 112 cm^2, and the coil has 230 turns and an area 19 cm^2. I know that mutual inductance = (N1 Φ1)/ I2 but I have no idea where to begin since they don't provide the...

Homework Statement 1.A circular coil, with radius of 10 cm, and 25 turns, rotates in a constant magnetic field of strength 2.4 T, with the axis of rotation perpendicular to the direction of the magnetic field. A. If the coil rotates at a frequency of 50 Hz, what is the induced peak voltage...

Homework Statement The component of the external magnetic field along the central axis of a 50 turn coil of radius 5.7 cm decreases from 1.8 T to 0 T in 3.3 s. (a) If the resistance of the coil is 2.8 ohm, what is the magnitude of the induced current in the coil? (b) What is the direction...

Homework Statement A bar of soft iron of cross sectional area A and relative permeability μ is bent into a ring of radius R. The bar is wound with n turns of a wire carrying a current I. Deduce a value for the magnetic field in the iron, explaining your assumptions. (b) A narrow gap of...

Hi everybody. I have a question on a magnetic field of a coil with N spire . I know the magnetic fields on point P that it has a about distance form coil center and staies on the central axis of the coil. Is possibile to determinate the magnetic filed of the coil on point P that does not stay...

I also have a membership at scienceforums.net and posted this to try to figure out what went wrong, but my post has been up for a week with 100 views and 2 replys both saying that they have no idea what I'm talking about. Hopefully I will have better luck here. Quick introduction: I am 16...

I was wondering if there is a simple way to make a power inverter (DC to AC) that is solid state, and does not use a coil. Actually, I'm not sure if there is a difference, but "pulsing DC" might be more what I'm thinking. I don't necessarily need the current to flow in reverse, but just to...

I need to calculate how much voltage is created as a magnet passes over a coil. However I don't know a formula to calculate this. Could anyone help me, I just need a formula PS: sorry, spell check does not work

The idea is as it follows: We have an homogeneus magnetic field that was increased from 0 to Bf. It induced a certain current (that accumulated to a charge Q) in a circular coil of radius a and resistivity \rho constant. The question is, what would be the charge Q' when the coil is twisted...

See attached problem: http://img72.imageshack.us/img72/4791/65321158jp4.th.jpg The answer is 6.9 × 10−4 Wb - by multiplying the Area by the magentic flux density. Mq is, why does one not multiply this by 850 (number of turns) in order to find the answer. Thanks

Consider a toroidal coil of rectangular section of N turns, for every one of which circulates a stream I. The inner radius of the coil is a and b is the exterior and the height is h. The core of this coil is a material inhomogeneous in such a way that their magnetic permeability just depends on...

I would like to know..what is the concept of rotating a magnet above a coil of wires to produce electricity.. what is the factor affects the power of electricity produce.. 1)Is it the number of coil? 2)is it the power of magnet? 3)is it the distance between magnet and coil 4)or anything...

Homework Statement A solenoid of cross-sectional area 2*10^-4 m^2 and length 0.5m having 500 turns is to be used to produce a uniform magnetic field some distance close to the center of the solenoid. Find the current that must flow in the solenoid to produce a magnetic flux density of 3*10^-3...

Hi.. I have a question about AC magnetic field, wondering if you can help me understand this. For a DC solenoid coil, We can say Magnetic field H=N*i/L (simplest form) For an AC input, H=N*isin(wt)/L ; H(rms) = N*i/L (i is RMS value) As long as the current i-rms is kept constant...

I want to calculate the electrical parameters of solenoid coil of a valve for a given spring force. I know the force required to pull the solenoid plunger through a given distance against a spring, is there any formula to find out the required voltage, number of turns of coil winding & current .

Homework Statement How will a coil's self inductance change if you unwind it and then re-wind half of the length of wire into a coil with the same diameter but with half of the number of turns? The answer is that it will decrease by 1/4, but I don't understand why it isn't 1/2 instead...

Tesla Coils! How many here have built Tesla Coils? I am wondering becouse i am currently building my seconed Tesla Coil. (My first one barly worked, pretty much made out of hot-glue) And I'd like some group to dump all my questions on, only other forums I know of to post questions...

I am a student at Colorado State. Can someone in this forum help me with building an AC coil either an air core coil or C-frame iron or steel with so many turns of copper wire that has a maximum magnetic field of 0.2 T and its frequency range is 100KHZ to 100MHZ. I am searching on the internet...

Homework Statement This is part of a lab I did, I am working on the writeup now. We placed a coil of wire inside of a Helmholtz pair, with 20V of 60Hz AC through the Helmholtz pair. The coil inside was connected to an oscilloscope and the induced voltages were recorded. I now need to...

Hi I am working on a project to do a coil simulation using COMSOL to determine inductance and resistance variations with frequency. I have a CAD file for the geometry but I need help because I am having serious difficulties with the rest. Can anyone help pls? thanks alot

Homework Statement A coil with 170 turns, a radius of 5.0 cm, and a resistance of 12 ohms surrounds a solenoid with 230 turns/cm and a radius of 4.7 cm; see the figure. The current in the solenoid changes at a constant rate from 0 to 1.8 A in 0.11 s. Calculate the magnitude and direction of...

Hi, i am working in a motion capture project one of its parts is a sensor i need a formula of the voltage generated in the coil due to moving in electromagnetic Field from an inducer i think it depends on ( B , cosθ , µ , N , L , r ) i post this thread in another forum but no one answer...

Homework Statement A 32 turn circular coil of radius 4.60 cm and resistance 1.00 is placed in a magnetic field directed perpendicular to the plane of the coil. The magnitude of the magnetic field varies in time according to the expression B = 0.0100t + 0.0400t2, where t is in seconds and B is...