Solenoid Definition and 752 Threads

I am a mechanical engineer and am having to do some calculations concerning magnets and solenoids for a project I am on. I have a solenoid (defined by number loops, current and cross sectional area). Inside the solenoid is a rare Earth bar magnet of some length, initial mis alignment...

The construction of and excitation of an infinite, straight, right circular solenoid of radius a, with N turns per unit length, are such taht tis current I(t) is the same everywehre along its length and is changed very slowly in time. Show that the fields far from the solenoid are approximately...

A square loop of wire surrounds a solenoid. The side of the square is 0.1 m, while the radius of the solenoid is 0.025 m. The square loop has a resistance of 30 W. The solenoid has 500 turns and is 0.3 m long. The current in the solenoid is increasing at a constant rate of 0.7 A/s. What is the...

Homework Statement A solenoid 1.7 cm in diameter and 30 cm in length has 4000 turns and carries a current of 5 A. Calculate the magnetic flux(in Wb) through the circular cross-sectional area of the solenoid. Since this is a very long solenoid, you may use the simplified magnetic field formula...

Homework Statement A long cylindrical rod (permeability u , length L0, radius R) is partially inserted into a long solenoid (length L1, radius R, turn density n, and fixed current I) How large is the force on the rod? Our hint is to first calculate the total energy in the field...

Homework Statement The problem can be found http://whites.sdsmt.edu/classes/ee382/homework/382Homework1.pdf" (the last one), along with a picture of the circuit. Homework Equations R = l/(µS) mmf = NI = ΨR B = Ψ/S The Attempt at a Solution I've never done a problem like this...

Homework Statement Through the bigger coil with N = 10,000 turns of wire and length of L = 30 cm is flowing electric current of I = 5 A. Inside the big coil we insert a smaller coil with N(1) = 500 turns, length of L(1) = 3 cm, and a radius r = 1 cm. The electric current flowing through the...

This isn't really a homework problem, I just need to know how to do a problem similar to this one for the final and I don't want to fail, so I posted it here. A solenoid with n turns per unit length, length l and radius a (l>>a) has a current I(t)==Io sin(wt) [w is omega], where I and w are...

Im in the process of making a coil gun and I need to do some calculations but I am not sure how to get the Force of the magnetic field. I know how to claculate the field and I have the values of my capacitors that I will be using to discharge the current into the magnetic wire. Can someone...

Homework Statement A variable current I(t) = 2Acos(100Hz*t) is passed through a long, thin solenoid of R = 2,5 cm and 900 spirals per meter in length. Calculate the induced EMF inside the solenoid and the self-inductance coefficient L. Homework Equations Magnetic field inside a long...

Homework Statement A long solenoid with 1000 turns per meter and a radius 2.00 cm carries an oscillating current given by I = (5.00A) sin (100 pi t). What is the electric field induced at a radius r = 1.00 cm.from the axis of the solenoid? What is the direction of the electric field when the...

We always talk about the magnetic field produced by solenoids, straight wires of current, and rings of current, etc., but why do we never talk about the ELECTRIC fields produced by these geometries? I mean, there are CHARGES, right? So there must be electric fields present, right? Or am I wrong...

Could someone show me how to calculate the magnetic moment of a solenoid, it's an air gap solenoid, 12V power supply, 1200 turns, 6cm long, the current works out to around 5-7 A and uses 1mm wire (18 AWG or 19 SWG). the flux density works out at about 3 Teslas. If what I'm using it for...

This is not a homework problem due. It's practice. I have the answer of .198mV. I don't know how to get it. Homework Statement Homework Equations \phi_b = \int \vec B \cdot d\vec A E = -\frac{d\phi_b}{dt} The Attempt at a Solution The magnetic field due to the solenoid is...

I'm trying to write a program to simulate the fields generated by a solenoid but I've hit a bit of a brick wall. There is a vast amount of examples and information on the field generated inside a solenoid however they all assume that the field outside is negligible and as such I have been having...

Homework Statement demostrate that the self inductance of a selonoid (L) that have: length = "l"; radius= "a" ; number of turns per unit of length= "m" , is:Homework Equations L = pi*(m2)*(a2)*Uo*[ ( (l2)+(a2) )1/2) - a ]The Attempt at a Solution It is suposse that the selfinductance is just...

Homework Statement I have the following information about the problem. i have the speed of an electron = v the diameter of a circular path = d the length of a solenoid = x the current that the solenoid carried = I I need to find the number of turns in the solenoid. Homework Equations i...

Homework Statement A solenoid with a radius of 8.0 10-3 m and 170 turns/cm is used as an inductor in a circuit. When the solenoid is connected to a source of 15 V rms at 22 kHz, an rms current of 3.7 10-2 A is measured. Assume the resistance of the solenoid is negligible. (a) What is the...

What would be the magnetic field of a solenoid if the wire of the solenoid itself is made up of another solenoid? I would be glad to hear any explanation about it.

Homework Statement A solenoid of length 3.7 cm and diameter 0.95 cm is wound with 160 turns per cm. The current is decreasing at a rate of 38.0 A/s. (a) What is the induced emf in one of the windings? (b) What is the induced emf in the entire solenoid? Homework Equations emf =...

Homework Statement This is a personal enquiry, not a homework question. I think I understand but would like confirmation. In a modified Thompson's Jumping Ring apparatus, the solenoid is horizontal and the ring free to move on the iron core. If the ring is either side of the central...

Homework Statement A long solenoid has 100 turns/cm and carries current i. An electron moves within the solenoid in a circle of radius 2.20 cm perpendicular to the solenoid axis. The speed of the electron is 0.048 c (c = speed of light). Find the current i in the solenoid. Homework...

Given a solenoid we can find the field inside and at the ends by B=urNI. Now, what is the field strength at some x -axial distance away from the solenoid? What force will this field impart on a piece of iron?

I am trying to make a an electric door lock releaser. I am going to use a solenoid to make an electromagnet that will pull down a handle to release the lock. The electromagnet has to act from a distance of 1 cm. And it has to impart a force of at least 10 N. The problem is to design the...

How can you argue, by symmetry, that the vector potential inside a solenoid depends only on \rho, the perpendicular distance from the axis of the solenoid? And how can you argue that there is only a \hat{\phi} (azimuthal) component of the vector potential, such that \vec{A} takes the form...

If you reverse the direction of the current flow, will the direction of the magnetic field reverse?

Recently I found that, if I apply a sinusoidal current to a long solenoid I get a radiation from it. It is completely theoretical result. I want to verify whether my result is correct or not. For this verification I need either some experimental result or some theoretical explanation whether it...

A bar magnet is being pulled away from one end of a solenoid, eg N pole of magnet nearest to solenoid. I've learned that the current induced in a solenoid is such that the magnetic field it creates opposes the change in flux through the loop. But what if the solenoid is in an open circuit? Will...

Homework Statement A constant current of 1A through a solenoid creates a magnetic flux of Φ=20mWb measured on the solenoid axis in the middle of the solenoid. What is the value of the solenoid inductance? Homework Equations here's what I've managed to find on the subject...

Dear all, i met a problem that i couldn't get the on axis field of a finite solenoid that integrating from a thin shell solenoid equation. The thin shell equation link: http://www.netdenizen.com/emagnet/solenoids/thinsolenoid.htm And the on axis finite solenoid equation link...

Hello, I've been attempting to learn how to use COMSOL and ANSYS to create and model a simple solenoid (iron core, 1000 turns of 26 AWG Cu wire, 1 Amp, 0 Hz etc), ever since I realized my Department always had a license to both packages :rolleyes:. I've done this using FEMM, and fairly...

Homework Statement For a long solenoid, the magnetic field strength within the solenoid is given by the equation B = 5.0t T, where t is time in seconds. If the induced electric field outside the solenoid is 11 V/m at a distance 2.0m from the axis of the solenoid, find the radius of the...

Hye everyone~ I am Jesse and I'm new to this forums :smile: and i really need your help so let's get straight to the prob.. can anyone tell me what are the choices i can use if i want to power up a solenoid valve installed in a hazardous area. I've heard about powering it thru system...

i've been looking for an equation to find the force exerted on a ball bearing in a solenoid (on axis) using the magnetic flux density but i have no idea where to look, I've googled it, I've tried online physics enciclopedias but i just can't find it. I am going through town today and I am going...

ok so I am making a few solenoids for a little project I am doing at home, I am making a mass driver. i thought it would look good on my uni application, and it would be fun to build. anyway, I am using the equation http://img229.imageshack.us/img229/5841/equation1solenoidimg.png to find the...

Homework Statement I want to know why Ampere's Law can sitll be applied/valid if the Amperian surface is drawn as a rectangle which encloses a whole solenoid. Normally the rectangle would just include one side of the solenoid. Homework Equations The Attempt at a Solution When...

I’m making a solenoid and I’m trying to work out how much force it exerts on an object X meters away from it. I’m using F=BIL to get the force but I don’t know the equation for getting the magnetic flux density of the solenoid other than B=(uNI)/L but that’s just for the centre and I need it for...

Hi, I red that in Franklin's book "Classical Electromagnetism" there's off-axis magnetic field of a solenoid solution...well I need that but can't get the book... so I'm wondering if anyone has that solution for magnetic field of a solenoid analytically? It's important and I would be...

Hello , I have been wanting to find out the how heat generation of a tubular solenoid (pull-type)actuator is calculated? Secondly, why do most solenoid design use a plunger with a flat face/conical surface area . If I am looking for 1mm of stroke.. and a force output of 2500N, what apex...

I've just recently seen the term "inductor" for the first time and it kind of threw me off. I'm just wondering, what's the difference between an inductor and a solenoid, if there is one?

given a long solenoid, with a radius of R (R<<L), a current of I flows throught it. find the magnetic field at point A which is located at a distance of R from the solenoid on the solenoids line of symetry. HOW DO I DO THIS?? the only thing i see that i think i need to do here is somehow...

given a long solenoid, with a radius of R (R<<L), a current of I flows throught it. find the magnetic field at point A which is located at a distance of R from the solenoid on the solenoids line of symetry. HOW DO I DO THIS?? the only thing i see that i think i need to do here is somehow...

1. The problem statement, all given/known data A bar magnet is positioned at the mouth of a solenoid. The current indicated in the solenoid is then turned on. (Assume the solenoid is a lot bigger than the bar magnet.) Gravity and friction can be ignored. Describe what would happen, and...

Hey guys I have been wondering do the cross-sectional area of the copper wire affect the solenoid?So far I only know that the cross-sectional of the core material , turn of wire (N) , leakage , etc. affected it.Have been wondering for so long since the formula given in many website doesn't state...

Some students were performing an experiment involving 2 solenoids in a line, a power source attached to the primary, and a globe attached to the secondary solenoid. A crude depiction of the setup is as below. /////// /////// <---- Rod inserted here Pri . . . Sec An iron rod was...

Hi, this isn't an actual question, but is a confusion inspired by a question I did (hence me not using the template). I'm having trouble with this example. I'm talking about a solenoid (with core, but doesn't really matter), with n turns per unit length, and a current I_0 t going in. \vec{z} is...

Homework Statement "A light bulb is connected to a coil of wire. If a magnet is passed back and forth through the coil the bulb will light up. Why?"Homework Equations The Lenz Law isn't really an equation, but it states that: "The magnetic field of the induced current is in a direction to...

Hi, I am trying to design a simple water valve that opens a plug in a small water reservoir until its empty. So far I have a solenoid coil wound around a hollow core plastic pipe with a cylindrical rare Earth magnet inserted halfway into the pipe with a 'plug' attached to the top of the other...

A small loop of area A is placed inside a long solenoid that has n turns per meter and carries a sinusoidally varying current of amplitude i. The central axes of the loop and solenoid coincide. If i = i0sin ωt, find the emf in the loop. EMFinduced = - d(\phiB)/ dt \phiB=BA Bsolenoid=...

imagine a very long solenoid with radius R ,n turn per unit length , carry current I.coaxial with the solenoid are two long cylinder shell of length L-one ,inside the solenoid at radius a ,carries a charge +Q,uniform distributed over its surface;the other ,outside the solenoid at radius...