Coil Definition and 864 Threads

Hi, I'm new here and I apologize up front if my terminology is incorrect. I've been a Civil Engineer for over 30 years, but am very far from an expert in electrical. Sorry if this is an elementary school level question for you guys! I am hoping someone here can either give me a hand or point me...

When applying Noether's theorem to a coil of wire under reflection transformation invariance, what Hamiltonian would one use as as the extermized function? I realize that electromagnetism is not invariant over reflection transformations, that's what I am trying to prove.

I'm making a coil gun for a project, and ran into a few problems. I used a circuit from a disposable camera, which had a capacitor and charging circuit. I used two wires attached to the capacitor to connect the circuit to my solenoid. However, after charging the capacitor, nothing seems to...

I'm not sure if this is the right place to post this, but at this point I'm a little bit desperate, so hopefully I can get some suggestions here... I'm working on a project in which I'm building a Tesla coil. We're using a 15kV transformer, about 15nF capacitance (six 10 nF (16 kV rated)...

Homework Statement A coil of wire is connected to a power supply, and a current runs in the coil. A single loop of wire is located near the coil, with its axis on the same line as the axis of the coil. The radius of the loop is 3 cm...

Homework Statement A circular conducting coil with N=100 turns and radius "r" is oriented in the xy plane. The leads of the coil are connected to a circuit with resistance "R." A time varying external magnetic flux density "B" is applied along the z-axis. What is the total magnetic flux...

Linked below for exact specifications. I haven't heard of this one of Tesla's inventions used for anything, does anyone know if it works, surely it does if it was granted a patent? If so why and what is it used for or if not why not? Anyone? Thanks very much! Link...

Hello everyone, I have been tirelessly searching the net trying to find out how to calculate the distributed capacitance of a multi-layer bifilar coil. Just wondering if anyone here can point me in the right direction?

A friend of mine grabbed a handheld 10,000 volt tesla coil (the metal end) in one hand and a florescent bulb-tube thing in the other, and showed me that he could light the florescent tube using the electricity from the tesla coil. My question is, why did it not shock him, and are there any...

Homework Statement A circular conducting coil of radius 2.8 cm is placed in a uniform magnetic field of .900 T with the plane of the coil perpendicular to magnetic field. Coil rotated 180 degrees about the axis in .222 seconds. If the coil is made of copper with a diameter of .900 mm, what...

i came up with a fractal that may have an application in electronics but i don't know what it could be used for. picture a coil wrapped around a coil and so on. picture a small wire half the gauge of a larger wire in which the small wire is wrapped around and the product is coiled around a...

what would happen if the secondary coil of a tesla coil was wrapped around the primary assuming they were both insulated? and if the secondary wire was half the gauge size of the primary then would the secondary have to be twice as long as the primary for the coil to fit when coiled around the...

Can someone please tell me why the formula for B at the center of a coil and the formula for B inside a solenoid give widely different answers in this problem? From Serway and Vuille, College Physics: "A solenoid with 500 turns, 0.10 m long, carrying a current of 4.0 A and with a radius of...

Homework Statement The Attempt at a Solution For letter A, my guess is ξ = dɸB/dt, ɸB = BA (since both magnetic field and the area are constants) After substituting, I ended up with a hanging \frac{d}{dt}.. I'm quite confused. For letter B, I don't know. Will I use the same...

what is the value of e.m.f acting upon charged point particle situated at the centre of a circular coil carrying a changing current

Homework Statement My son and I have built a wind turbine following the plans on: Build your own Wind Turbine Designed by Dave Mussell http://www.re-energy.ca/docs/wind-turbine-cp.pdf" . These plans were inspired by the Picoturbine: link to manufacturer and link to PDF. We used 30 AWG...

Are there any coil-cross sections equations?

Homework Statement In a rotating coil generator, the magnetic field between the poles of an electromagnet has the magnitude .40T. A circular coil between the poles has 120 turns and radius 4.0 cm. The coil rotates with frequency 5Hz. Find the maximum emf induced in the coil. Homework...

Hey I'm interested in designing a linear electricity generator (think magnetic piston moving back and forth in a coil housing) and was wondering if anyone could reference where I should look for designing the coils/magnets. Thanks!

Homework Statement A non inductive resistor takes 8A at 100 volts. What inductance of a coil of negligible resistance must be connected in series in order that this load can be supplied from a 220 volt 60 Hz mains. Homework Equations Z^2 = R^2 + XL^2 R=V/I XL = 2pi(frequency)...

I've been wondering for a while, a Rodin coil's magnetic field generation is the center as a strong open air magnetic field is it unique or is it easily duplicated with different wire configurations that might have this property in a stronger manner more easily. I have tried to find other...

I understand that the magnetic field in a solenoid can be approximated as being constant as the length of the solenoid tends to infinity, but I was wondering if anyone could show me or point me in the direction of a derivation of the precise magnetic field at any point within a single loop of...

Hi everyone, I am have been looking here for a long time, but today is my first day registered. I will be active from now on =). As my first post, I would like to know about the basics and advice about the solid state tesla coil. I would like to do it for my final year project. Is it advisable...

Hey, I am making an electromotor. How many turns of 0.4mm/26 Gauge wire should I make so as to run the motor at 9 Volts? (I`ll count the needed wire length assuming that 1 turn of wire = 8.5cm.) Thank`s in advance & please let me know if you need more info... :smile:

In my table lamp, there is only a switch, and a copper coiled sheets of steel. I am in K9 and would like to know what are those sheets for ? My second very fundamental question is when should we use an adapter ? Thank you

Could Someone explain exactly how Tesla coil works with necessary Mathematics and Science. The Wikipedia Article simply states facts but doesn't explain much anything. Well I can't understand this, In the secondary of the 115V/15KV transformer the transformed voltage is 15KV at 50Hz. Then...

Hi there, If you have a stream of protons passing through the inside of a coil of wire (coils of wire at 45 degrees to current of protons) and say the current of protons induced a certain current in one of the loops, would the current induced in one loop be equal to the current in the entire...

Homework Statement A coil of wire with 100 turns and a cross-sectional area of 0.1 m2 lies with its plane perpendicular to a magnetic field of magnitude 1 T . (a) Describe in your own words the meaning of magnetic flux (b) calculate the total magnetic flux passing through the coil. (c) If the...

Is there a formula for calculating the voltage and or current in a 2 meter length of coil? The coil being 30mm in diameter with 1mm thick wire coiled around 200 times (for ease of calculation so cable would roughly be 18.8m long) with a resistance of say 16 ohms. Magnet being a cylindrical...

Specific Heat Capacity Lab I conducted a lab where I heated 100ml of water using a heating coil with a current of 4A passing through it. The temperature data turned out beautifully, with the temperature rising evenly until it plateaued just under 100 degrees celsius as it began to change phase...

Homework Statement what is the emf if the magnetic flux through a coil at 50 turns is reduced from 0.5 weber to 0 weber in 0.2 seconds? Homework Equations [b]3. The Attempt at a Solution : dont even know how to get started with this problem

I have been wondering how to calculate how much current and voltage would be induced through a 2m length of coil when a magnet passes through. The coil being 30mm in diameter with 1mm thick wire coiled around 200 times (for ease of calculation so cable would roughly be 18.8m long) with a...

Homework Statement Calculate the length l of an an iron-free cylindrical coil if it has 9400 turns (N), a thickness of 0.6cm and an inductance L = 68 mH. Take magnetic field constant \muo = 4\pi x 10-7 Wb/Am (a) l = 63mm (b) l = 54mm (c) l = 46mm (d) l = 36mmHomework Equations L = N2 \muo...

where coil store energy?? dear all well many times when we speaks about coils , they say that coil store energy like cap. stors charges on its plates , the coil store the magentic energy inside its core so in case of air coil where the energy is stored ! thanks all bye

Homework Statement Hi I am really stuck on this question. It got handed out to us this morning and is due in Wednesday of this week. Any help would be great thanks. A circular solid coil consisting of a circular disk of radius R = 20mm and mass M = 50 g pivoted through its diameter. It has...

Homework Statement A square coil (25 x 25 cm) that consists of 50 turns of wire rotates about a vertical axis at 1000 revolutions per minute. The horizontal component of the Earth's magnetic field at the location of the coils is 2 x 10-5. Calculate the maximum voltage induced in the coil by...

Hi All, Long time reader, first time poster. I'm currently building a tesla coil. here are the details: 1.) I'm using three parallel NSTs that each output about 6500 volts at .9 amps. 2.) I'm using 4 high voltage capacitors that I built using two sheets of aluminum siding with...

Homework Statement A single rectangular loop is placed distance C from a wire of current I. The dimensions of the loop are BxA. The loop and wire both lie in the same plane, and a is at right angles to I. Derive an expression for the mutual inductance, given that you found flux in a previous...

When finding for "L" is the value for "l" (length of coil) affected by the length of the core material. Or more specifically when one is working this equation for two coils yoked in series do you figure each coil separately?...and if NOT, do you include the length of the yoke? Here is a link...

I have a 3ph IEC contactor with 120v coil voltage. For some reason, the coil starts heating up like crazy when I run it. I have 121v on L1, 120v on L2 and 121v on L3. I re-connected all the wiring to make sure there were no loose connections but still it keeps heating up when I energize the...

Homework Statement A flat coil of wire consisting of 20 turns, each with an area of 50 cm2, is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 2.0 T to 6.0 T in 2.0 s. If the coil has a total resistance of 0.40 Ω , what is the...

Hey all, I'm new to this site, so bear with me here! First post woot! Homework Statement A bar magnet with magnetic dipole moment 0.5 A m2 lies on the negative x-axis, as shown in the diagram. A compass is located at the origin. Magnetic North is in the negative z direction. Between the bar...

I am trying to figure out how to program a 528 hz signal to emit and amplify through a copper wire coil

Hi guys, quick query (at least I think it's quick!). I know that, in a microphone, when a waveform passes through the electromagnetic field it resonates the diaphragm and in turn moves the induction coil set in the middle, creating a VARYING current... My question is: Is the varying...

Homework Statement A rectangular coil consists of 25 turns of wire forming a square 4cm each side. By considering the force on a current-carrying straight wire, calculate the torque acting on the coil when the normal is at 30 degrees to a magnetic field of 0.8T and 12 A are flowing...

I need some help to calculate the retardation of a magnet cylinder passing trough a coil with an open end which lies horizontal. If you have a 0.5 m long circular coil which is 50 mm in diameter and a circular magnet cylinder fitting into the rod. The magnet cylinder has an initial speed of 10...

Homework Statement What I actually need to find is the magnetic field at any point in space for an elliptical solenoid. I think the way to do this would be to find the magnetic field caused by an elliptical current loop, and then to use some kind of summation for multiple loops to get the...

Homework Statement A heating coil is to be made, from nichrome wire, which will operate on a 12 V supply and will have a power of 36 W when immersed in water at 373 K. The wire available has a cross-sectional area of 0.10 mm². What length of wire will be required? (Resistivity of nichrome at...

Okay, now I realize that this is from sci-fi, but I'm just wondering if it's possible to do this. In the movie, The Sorcerer's Apprentice, the guy uses Tesla coils to "make music." He said that when they fired, the did so at such a high frequency that it made sound. Is this possible?

Is anyone able to explain why someone wired this motor contactor circuit such that activating the coil is done by connecting the two leads to the following: contactor: Allen-Bradley 69A86 lead 1: 120V AC lead 2: 120V AC - Phase Shifted by 120 degrees So I guess the difference of the...