Solenoid Definition and 752 Threads

Homework Statement We have a solenoid of radius a, length L, with ends at z = +/- L/2. The problem is to use Ampere's law to show that the longitudinal magnetic induction just outside the coil is approximately B_z (\rho=a^+, z) \approx \left(\frac{2 \mu_0 N I a^2}{L^2} \right) \left(1+...

Homework Statement There is a solenoid with a magnetic field of a constant magnitude B. In this solenoid is a charged particle, initially at rest, at a certain distance r from the axis of the solenoid. After a certain amount of time, the magnetic field is instantaneously flipped in direction...

When I have an infinite solenoid , The b field lines point straight up the solenoid and the field is zero outside. But i thought that the field lines have to wrap back around on themselves. Does this not apply in this example . Or am i crazy?

1. Can a solenoid connected to alternating current generator be used as transmitter of electromagnetic radiation? 2. Can a solenoid be used as a receiver of electromagnetic waves? I think point 2. is possible, since alternating magnetic field will induce voltage in the loops of solenoid...

Homework Statement Hi guys. Electrical engineering student here trying to get some real physics under his skin. I'm trying to derive the field and ultimately the inductance of a finite solenoid based on the spiral shape of the windings (because I assume - for no good reason - that the exact...

Homework Statement There is an infinetly long solenoid with current I, radius R, and N loops/unit length. Find the B field in the axis of the solenoid. Homework Equations The Attempt at a Solution So that eq. can be narrowed to B integral dl = Uo I the only problem is...

Homework Statement The turns for a long solenoid are wound to fill the space between two concentric cylinders of fixed radii, r1 and r2. Show that, for a given magnetic field density along the axis of the solenoid, the heat dissipated in the windings is independent of the size of the wire...

The magnetic flux density B( in tesla ) inside the solenoid and parallel to its axis is given by the expression B= permeability of free space x n x I, where n is the number of turns per metre length of the solenoid my question is so for example, if n = 100turns in 1m and I = 2Ampere...

Hi all Physics (masters) I was reading a paper on the faraday's induction experiments; i didn't quite understood the reason why is current induced into a solenoid. There is this solonoid and a Permanant magent is pushed inside the solonoid and we observe that a current flows (by a...

A solenoid of radius 0.0523m is made of a long piece of wire of radius 0.002432m, length 54.0m, and resistivity 7.4x10^-9 \Omegam. The solenoid is closely wound with a single wire thickness. The permeability of free space is 1.25664x10^-6 Tm/A. Find the magnetic field at the center of the...

Homework Statement 6. A solenoid 25.0 cm long with a cross-sectional area of 0.500 cm2 has 400 turns of wire and carries a current of 80.0 A. Calculate: a) the magnetic field in the solenoid; b) the energy density in the magnetic field if the solenoid is filled with air. (2 marks)...

How many turns of wire would be on a solenoid carrying a current 4.9 A if the solenoid is 17 cm in diameter, 248 cm long, and the field at the center is 2.9 × 10-3 T? I can't seem to get the right answer... I plug the values into B=n*u0*I and then solve for N. I know that n=N/length

Homework Statement 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...

Homework Statement 1. Homework Statement A 20cm long solenoid has 4000 turns of wire. Insiude this solenoid is a second on, also 20cmlong but with 2500 turns of wire. If a 2.5 A current flows in each solenoid in the same directon, what is the magnetic field inside the inner solenoid...

Homework Statement A 20cm long solenoid has 4000 turns of wire. Insiude this solenoid is a second on, also 20cmlong but with 2500 turns of wire. If a 2.5 A current flows in each solenoid in the same directon, what is the magnetic field inside the inner solenoid? Homework Equations...

We are currently learning about solenoids in my physics class, and am very confused about where this potential drop comes from across a solenoid. I understand that an opposing electric field is created when a switch is first opened because of Faradays Law and the fact that the magnetic flux...

Homework Statement A soft iron bar in a solenoid is placed in a circuit. There are two compasses, 1 is on the West side of the iron bar and the other is to the North. The circuit switch is open, which way will be compass needles be pointing? Which way will the compass needles be pointing if...

I wanted to know how the magnetic field of a solenoid would be affected if a copper/iron pipe section was put into its center. In other words, what would the resulting magnetic field be if I simply wrapped a coil around a metal pipe section without removing the pipe afterward? Will there be...

Say I have an ideal (long and tightly wound) solenoid, and I put a ring of wire around it (large ring). Then, by Faraday's law, if I put a current through the solenoid there will be an induced current in the wire ring around the solenoid. But if there are no B-field lines crossing my ring of...

Homework Statement Solenoid is 1.8m long and 75 cm in diam. one layer tightly wound with wire that has diam 2mm. what current needs to run thru to get 1.5T Homework Equations N=2piR/(L) where R is radius of solenoid and L is wire lenght The Attempt at a Solution Once I find how...

Homework Statement You have 12m of 0.50mm diameter copper wire and a power supply capable of passing 17A through the wire. What magnetic field strength would you obtain inside a 2.0-mm-diameter solenoid with the wire spaced as closely as possible? Homework Equations The Attempt...

Homework Statement You have 12m of 0.50mm diameter copper wire and a power supply capable of passing 17A through the wire. a)What magnetic field strength would you obtain inside a 2.0cm diameter solenoid with the wire spaced as closely as possible? b)What magnetic field strength would you...

Homework Statement You have 12m of 0.50mm diameter copper wire and a power supply capable of passing 17A through the wire. What magnetic field strength would you obtain inside a 2.0cm diameter solenoid with the wire spaced as closely as possible?Homework Equations B=u0nIThe Attempt at a...

Hi, I've have been searching for help in calculating the magnetic field strength at any given position outside a solenoid. I can use Biot-Savart's to get the field along the axis of the solenoid but how does the field vary perpendicular to the axis of the solenoid, for example. Rob

According to widely known formulas, the inductance of a long straight solenoid will remain practically the same if we bend it into a toroidal solenoid. It seems to be a contradiction, because the magnetic path length of a straight solenoid is more than two times greater.

I have a solenoid which has a current passing through it which increases linearly with time. I have proved that the energy stored in the magnetic field is equal to the energy being pumped in according to the surface integral of the poynting vector. This implies the energy stored in the electric...

Can anyone explain the concept behind changing of inductance of a solenoid (when AC current is passing through solenoid) on moving a metal sleeve (hollow metallic pipe) over the solenoid enclosing the solenoid.

Hi, I've been trying to learn about iron core solenoids and I'm having trouble finding information on a concept (probably obvious but I'm new to this). I've been looking at the equations for iron core solenoids online, and it's alluded to that these equations only hold true when the proportion...

Homework Statement Thin Shell Solenoid Homework Equations General Case Formula Found: http://www.netdenizen.com/emagnet/solenoids/thinsolenoid.htm" The Attempt at a Solutionplugged in variables and got .00062919475 T 4 other attempts were made using trivial solutions. Even tried finding...

I have a toy that is mounted 4 feet above the floor on which there are 3 pushbutton DSTP switches that I would like to actuate intermittently with my feet. I believe that I can do this by building a device that pairs 3 appropriately positioned solenoids with 3 momentary SPDT footswitches all...

Dear all I just joint with the group, I want to make solenoid self. I need plunger moving more 100 times/s, with strong force. anyone can help me to make this solenoid? and what material are suitable to make it? thanks for attention

Hello I have a problem that I can't understand... I am putting kerosene pressurised to 160psi through a 1/4" BSP solenoid with 13mm orifice. On the out port of the solenoid is a 1/4" BSP to 2mm ID nozzle. The idea is it sprays out a stream of kerosene. The kerosene is provided by...

Homework Statement I am building a coil gun with a single solenoid. I am going through the equations I know for magnetic force and others but I don't know if I am finding the force the wire feels or if it will be the force the projectile undergoes. Homework Equations F=qvB (assuming...

I've attached a diagram of a bar magnet being plunged into a solenoid. I'd like someone to explain the direction of the current please. Why do both arrows indicating current move upwards? Using the right hand grip rule i understand the north pole being in the position it's in. I get a...

1. Magnetic resonance imaging needs a magnetic field strength of 1.5 T. The solenoid is 1.8 m long and 75 cm in diameter. It is tightly wound with a single layer of 2.20-mm-diameter superconducting wire. 2. B = mu0BI / l 3. Is there a way to do this without finding N? Either way...

This is not a homework. I am just pretty confused about a problem (with solution!) I saw in the internet found here: http://www.transtutors.com/physics-homework-help/electromagnetism/Electromagnetic-induction.aspx The part I am confused is the mutual inductance part. Here I repeat the question...

Solenoid Passing through square coil--Finding electric field Homework Statement A very long solenoid with n turns of wire per unit length and radius b carries a current I(t) which decays with time as I(t)=I0e-t/T. The direction of current in the solenoid is as shown below. The solenoid passes...

Homework Statement A solenoid is designed to produce a magnetic field of 2.2 * 10^-2 t its center. It has a radius of 1.6 cm and a length of 44 cm, and the wire can carry a max current of 13 A. The first question was what minimum number of turns per unit length must the solenoid have...

1. MRI (magnetic resonance imaging) is a medical technique that produces detailed "pictures" of the interior of the body. The patient is placed into a solenoid that is 40 cm in diameter and 1.0 m long. A 100 A current creates a 5.0 T magnetic field inside the solenoid. To carry such a large...

1. The figure shows a five-turn, 1.0-cm-diameter coil with R = 0.20 ohms inside a 2.0-cm-diameter solenoid. The solenoid is 9.0 cm long, has 130 turns, and carries the current shown in the graph. A positive current is cw when seen from the left. Determine the current in the coil at =...

Let me preface by saying that I am a freshman in an introductory level Electricity and Magnetism course. My professor has assigned this problem, as he briefly introduced the idea of vector potentials, along with curl and divergence operators. I am VERY much lacking in knowledge of any of these...

Homework Statement Assuming we have equal volumes in both scenarios, which would maximize the magnetic field in a solenoid: a thick and short wire or a thin and long wire. Homework Equations B=(m)(constant)(I)/(2R) m= the number of layers of wireThe Attempt at a Solution The answer is clearly...

ok, the magnetic field through a single ring is n\muI , so the flux is BAcos(theta), with cos(theta)=1, flux = BA = piR2n\muI so why for the entire solenoid flux, it is now nL*the flux above? where L = length of solenoid shouldn't multiplying it with just n = number of rings be suffice...

Homework Statement Prove that the number of turns per length on a solenoid is equal to 1/(diameter). Homework Equations A= 2(pi)(R) The Attempt at a Solution number of turns= length/(2pi*radius) number of coils per length=(length/(2pi*radius))/length number of coils per...

Homework Statement A square 5-turn coil with sides .03 m long and carrying 2 A of current is placed in a uniform magnetic field of .07 T, as shown. What is the magnitude and direction of the force on each of the four sides? What is the magnitude and direction of the torque \tau on the...

Homework Statement A solenoid 2.50 cm in diameter and 26.0 cm long has 285 turns and carries 12.0 A. (a) Calculate the flux through the surface of a disk of radius 5.00 cm that is positioned perpendicular to and centered on the axis of the solenoid, as in Figure P30.36a. (b) Figure P30.36b...

I was wondering, are there significant effects on the performance of a solenoid when the solenoid is inside an external magnetic field? Does it affect the rate at which the magnetic field is established within the solenoid?

Hi, is there any rule that we can use to find the The length of a solenoid in the magnetic field Questions??

Homework Statement A long solenoid (black coil) with cross-sectional area A cm^2 and length L is wound with n1 turns of wire. A time-varying current i1 flows through this wire. A shorter coil (blue coil) with n2 turns of wire surrounds it. Use (uo)(m*kg/s^2*A^2) 1) Find the value M of the...

Homework Statement Determine the inductance of a solenoid with 650 turns in a length of 21 cm. The circular cross section of the solenoid has a radius of 4.2 cm. Homework Equations ? The Attempt at a Solution I've looked all over my textbook and can't come up with a possible...