Solenoid Definition and 705 Threads

Homework Statement Homework EquationsThe Attempt at a Solution The answer of 2c is : Current through A to the left. But I think it is to the right. By I=V/R, a reduced resistance R results in an increase of current through solenoid X. By B=unI, an increase in current causes the magnetic flux...

Our professor did a demonstration today for our physics II class. She was demonstrating electromagnetic induction with a solenoid and a metal ring. When she slid the ring down the solenoid and passed alternating current through the solenoid, the metal ring was flung upward off the solenoid. My...

Hello everyone! I found in my textbook that in order to calculate the pressure experienced by the surface of a long straight solenoid with ##n## turns per unit length and current ##I## we don't use the typical magnetic field ##B=\mu_0nI## on a loop of the coil , but a corrected magnetic field...

Homework Statement A coil with 140 turns, a radius of 5.2 cm, and a resistance of 11.0 Ω surrounds a solenoid with 200 turns/cm and a radius of 4.5 cm. The current in the solenoid changes at a constant rate from 0 A to 2.0 A in 0.10 s. Calculate the magnitude and direction of the induced...

I'm currently in conceptual phase of designing a coil gun. Thinking back to my physics 2 class-- and some of my independent studies-- I understand an EMF produced by a solenoid with current through the wires of it is strengthened significantly by a ferrous core, as seen by the classic experiment...

This is not a specific homework problem. It is a lack of understanding in theory relating to a lab report I have to write. We (my group and I) wrapped a 40 cm PVC pipe in copper wire (very densely and for almost the entire length), applied a current to it, and dropped a permanent magnet...

What happens if I have a permanent magnet outside an ideal solenoid? Does the permanent magnet rotate until the system reaches an energy minimum in its magnetic fields? Or does the permanent magnet fail to rotate because the magnetic field of the solenoid does not reach the magnet? Wouldn't...

Homework Statement For a lab we need the equation of the magnetic field strength produced by a solenoid a distance r away from it (outside of it). I tried looking online and couldn't find one that didn't involve a bunch of cross products or similar. Wonder if anyone knows the formula? I know...

Homework Statement A long air-cored solenoid has two windings wound on top of each other. Each has N turns per metre and resistance R. Deduce expressions for the flux density at the centre of the selenoid when the windings are connected (a) in series, and (b) in parallel, to a battery of EMF E...

Homework Statement Dr. X has an infinitely long superconducting solenoid with n turns per unit length and a power supply to drive arbitrary current wave forms through the solenoid's winding. The power supply can drive DC currents, temporarily ramped currents, sine wave currents, etc...

I am trying to calculate the magnetic field generated by an ideal toroidal solenoid by using the integral of the Biot-Savart law. I do not intend to use Ampère's circuital law. Let ##I## be the intensity of the current flowing in each of the ##N## loops of the solenoid, which I will consider an...

My text of physics, Gettys's, proves that the magnetic field on the axis of a solenoid, in whose loops, of linear density ##n## (i.e. there are ##n## loops per length unit), a current of intensity ##I## flows, has the same direction as the loops' moment of magnetic dipole and magnitude ##\mu_0...

In the presence of a constant magnetic field, does the action of rotating a solenoid (with a fixed amount of coils) produce an emf? Thank you!

Homework Statement (http://imagemap-generator.dariodomi.de/uploads/160725_010743_e42ea59f2569dfbV.png ) Homework Equations No equations or anything. Just need a visual concept understanding (11U Physics) The Attempt at a Solution The solutions say that all compasses should point east... So...

Homework Statement Hi everyone. I was reading through a book and came across the following question and explanation: " You are given two 200 meter strands of identical copper wire. With one strand you create a coil whose radius is 2 cm. With the second strand you create a 4 cm coil. Assuming...

I need help in calculating the magnetic field outside of an iron core solenoid at different distances. I have made an electromagnet by taking a 99.99% pure iron (5cm in length and 1 mm in radius) and wrapping wire over it. I have measured it's magnetic field at the end and cannot find an...

For a standard solenoid, I've found that B=μnI where μ = permeability of the core (4π×10^-7 for free space) n = number of coils I = current Firstly, is the permeability of soft iron 0.08, as I found? Primarily, however, I'm wanting to know if this still applies for a mutual induction apparatus...

Hello, I am a hobby machinist and also an EE PhD student. Recently I have been trying to make powerful solenoid actuators. I have succeeded, but they aren't perfect. I really want to make a professional, powerful solenoid. To give a sense of how deep I am going, here is what I have found so...

Hello all, I can't figure out why it is impossible to have a radial electrical field within a solenoid. My gut tells me there would be one. For that matter, I also don't understand why there is no radial component surrounding a current carrying wire. Considering gauss' law has not helped me so...

Hi, I wonder what would the path of magnetic field be in my case.I have a solenoid , it's a metal rod that has a winding in the middle of it, I need the magnetic field to come out of the rod not at the ends of it as is usually shown in pictures but at the surface side along each end of the metal...

Homework Statement A solenoid has a radius of 10 cm and a length of 50 cm. What I need to know to begin the problem is the number of loops ion the solenoid. Homework EquationsThe Attempt at a Solution One turn will have a length of 2(pi)r. I need to know the thickness of the wire around...

Homework Statement A 40-turn, 4.0-cm-diameter coil with R = 0.40Ω surrounds a 3.0-cm-diameter solenoid. The solenoid is 20 cm long and has 200 turns. The 60 Hz current through the solenoid is I = Io sin (2Πft). What is Io if the maximum current in the coil is 0.20A? Homework Equations Ncoil =...

How come the magnetic field outside a solenoid is practically zero? I've read reasons along the lines of: -The magnetic field cancels out on the outside. Of course the net force cancels out, but what if you have an object placed on just one spot? The force on that object clearly is not 0...

Homework Statement There is a simple set up with a cylindrical solenoid that is connected to a battery. Suppose the solenoid has a total resistance of 0.2 ohms. If the battery were attached to a regular resistor of R=0.2 ohms instead of a solenoid, the current in the circuit would...

I am confused about how the magnetic field of a solenoid is calculated in this image. Why is only the current going into the page included in calculating the magnetic field? Shouldn't the field be twice the amount calculated because there is a magnetic field generated by the part of the turns...

My goal is to make an electromagnet that delivers 100mT magnetic field on one end of the iron. The iron core has a diameter 2.0mm and length 0.1m. I am using a copper wire that can carry 2.3A of current, and I am using a DC power supply. I have been able to create a 100mT magnetic field on the...

First time posting here so excuse me if I don't know the rules so well. I figured this would be the best place to post this question. I'm trying to optimize the force produced by a solenoid that is no bigger than 15mm in diameter (D). My goal is to get just the right balance of number of wire...

Homework Statement Homework Equations Provided in the questions I believe. Here's the triangle from question two. The Attempt at a Solution QUESTION SET 1 TOP OF PICTURE A.) I didn't know how to just "guess" what the constant should be so I actually worked it out. I found the constant...

Homework Statement A circular solenoid with cross section A consists of N turns of wire. The leads of the solenoid are connected to a resistor with resistance R. A magnetic field B is exerted parallel to the normal of the cross section (from left to right, basically). At t0, this field has...

What happens when you apply power to a toroidal solenoid with a iron ring inside? Does the ring move? Does the speed of movement depend on the amount of power? Sorry if this is too easy, I have no education in physic.

Working on a wind turbine for a class project and making an attempt to add a brake. The idea is that the turbine will generate power at a certain wind speed and if the wind speed is increased, we would slow the turbine with a mechanical brake. We're using a 10V low-torque motor and have created...

i'm confused with N , it says that is the number of turns per meter , but is the meter the length of the wire or the coil height ?

Homework Statement A large number, N, of closely spaced turns of wire are wound in a single layer upon the surface of a wooden sphere of radius a. The planes of the sphere are perpendicular to the axis of the sphere (take axis to be horizontal), and turns are uniformly spaced per unit...

Hello, I have some problems with my solenoid calculations. I have spent many hours, on searching for Formulas, and answers, but exact answer I cannot find. I made 2 electromagnets, and then tried with solenoids. Last solenoid was made with 120 m long wire, 0,3 mm, center diameter was 12 mm and 4...

Homework Statement In a solenoid with 12 enamels for cm passes the current 2 A. Find the magnetic permeability of the iron bar inside it.(B0=1.508 T) Homework Equations B=μ0*I*N/l(length) The Attempt at a Solution We have N/l(length)=1200 enamels/meter B=4*10^-7*3.14*25*1200=0.003T Now...

Homework Statement I have a rectangular coil with length L and the cross-section's sides has length a and b (b>a). A wire is tightly wrapped around N times. Calculate the magnetic field inside the coil. Homework Equations The problem I have is that in class we were taught how to calculate...

Homework Statement a solenoid inductor consists of 200 closely spaced turns, length = diameter = 5cm. calculate inductance. Homework EquationsThe Attempt at a Solution H = NI/L L = N (flux) / I - you can't use this because the length is equal to the diameter. What equation do I use?

I am trying to create a solenoid with a high flux density, but I need the specifications (wire gauge, current applied, etc). The diameter of the core would be preferable around 15mm. The length can be pretty much anything reasonable. I need this for a project that requires a strong repulsive...

Homework Statement A solenoid contains 610 cycles, with a radius of 0.136m and a length of 0.87m. The current of the solenoid decreases linearly from the maximum value I0 to zero through the equation I(t)=I0−bt, where I0=0.31 A and b=0.21 A/s. What is the power output of the electromagnetic...

Homework Statement Suppose that you want to design a solenoid to control magnetically the central locking system of your car doors. This needs a magnetic induction at the end of the coil of 0.161 T. To be compact enough to fit next to the window winder mechanism, the coil can be only 3.03 cm...

Hello, and thanks for looking at my question. For starters, this is NOT a homework question, or a question I will receive any credit for except maybe a "hey, cool". The level of difficulty is roughly a junior-year Electromagnetics class homework quesiton, I suppose? My Question is rather...

I understand why slowing the current, causing a decrease in the flux, momentarily increases the current (stabilizing). I can use the right hand rule and Lenz's law to picture what is happening in that case. But why does increasing the current add resistance? The induced magnetic field is...

Homework Statement I found solution to problem 257 from "300 Creative Physics problems" hard to understand. In that problem we have very long solenoid with coil wounded in one layer. Data such as: density of turns, magnetic field at distance of 5 cm form the axis of solenoid and diameter (1 cm)...

Hi everyone, I'm having some fun building solenoids for a project. I can't just leave "well enough" alone... I want to know how these things really work! I understand the concepts behind Faraday's laws, current in a wire, etc... What I would like to find out is which gives more force to the...

I was reading http://www.rossdecco.com/pdf/how_a_dc_solenoid_works.pdf about push and pull solenoids. I don't quite understand what differentiates the two in terms of construction. What I have is a copper wire wound around a tube and the ends are attached to a battery, like in this I believe in...

Homework Statement A finite solenoid with "N" turns of wire, "L" length , "R" is the radius of the solenoid and passes through it a current "I". The objective is to calculate "L" of a finite solenoid. Not the basic formula ##L=\frac{\mu_0·N^2·S}{Length}## which is for a infinite solenoid. See...

Homework Statement A long solenoid has current I flowing through it, also denote N as the turns per unit length. Take its axis to be the z-axis, by symmetry the only component of the magnetic field inside is Bz. Find the magnetic field at the center of the solenoid (on the axis). Also, find the...

Hi, I'm trying to calculate the length of wire that I need to wound a coil using a spool and wire of known dimensions. I was trying to use this converter but I'm not getting good results: http://www.had2know.com/technology/solenoid-coil-wire-calculator.html For instance: with a wire radius of...

Homework Statement Iron core solenoid, with 50 turns per cm (5000 per metre) Current = 0.2A Measured B field = 1.58T Calculate: i) The applied field, Bapplied ii) The magnitude of magnetisation, M, of iron alloy Homework Equations For a long solenoid, Bapplied=μ0nI And, generally...

If you have a one solenoid inside another (with the same number of coils of wire) the current is going through the inner one. How does the induced EMF in the outer one depend on the frequency of AC in the inner one