B-field Definition and 103 Threads

http://upload.lsforum.net/users/public/m28175Untitledw43.jpg Q 21 why the is not downward?? it gains weight! Q22 why the direction is not out of paper, by right hand grip rule, 4 sides of the wire can produce a B-field which is out of paper!?

1. The figure shows an end view of two long, parallel wires perpendicular to the xy-plane, each carrying a current I=5.00A but in opposite directions. What is the magnitude and direction of the B-field at point P that is produced by the current in the two wires? 2. B=(μo/4pi) integral...

Here's the question ------------------- Here's my attempt using energy approach. However, I'm kinda stuck. how do I solve this DE to get the expression for v(t)?

Hey I have this problem Homework Statement A source which emits a line at 500nm is found to exhibit the normal Zeeman effect when placed in a magnetic field. Calculate the magnetic field given that the separation of adjacent components in the Zeeman pattern is 12.0pm...

If you have a solenoid positioned along the z axis... ...how would one find the b-field at slight deviations of x and y? I have been googling for hours and can't find anything other than the fact that it is very difficult! Thanks guys!

Homework Statement (Sorry, I don't know how to use latex) Solve the TDSE for a spin half nucleus in a B-field where B_z = B0, B_y= B1 cos(ωt) and B_x = B1 sin(ωt). Use vector and matrix representation. You will get coupled differential equations for a and b, look for solutions of the form a =...

Homework Statement A 25-turn coil has a radius of 1 cm and it is carrying a current of 1 A. The coil is in a constant B-field of 1 T (directed along the coil's axis). The coil is moving perpendicularly to the B-field at a speed of 1 m/s. a) Is there an Electromotive force induced in the...

Consider the following "classical" example: ^{}_{} A system Σ' moves away from a system Σ with relative velocity v in the direction of z'z axis (their origins concur at time t=t'=0). A charge q is located in the origin of Σ' and moves along with it, while an observer sits at (0,yo,0) in Σ. The...

[SOLVED] Rotating Square Loop in Constant B-field Homework Statement Homework Equations \epsilon = - \frac{d\Phi}{dt} \Phi = BAcos(\theta) = BAcos(\omegat) d\Phi = -BA\omegasin(\omegat) The Attempt at a Solution I'm trying to study for an exam and I've got this practice...

Hi I have a question regarding mu-metal, which I haven't beem able to find the answer to online. Say I have a current loop placed enclosed in a cylindrical magnetic shield made of mu-metal as shown in the attachment (red loop is the current loop). The shielding will prevent any B-field to...

Homework Statement Hi I have a current loop (see attached), and I have found the expression for the B-field along the axis of the loop. A particle moves through the loop, as also shown in the attached picture. Using the right hand, I let current run through the loop counter-clockwise, shown as...

Homework Statement A light bulb with resistance R is attached on a metal rod which is rotating around the point O on the figure. The metal rod is in contact with an electrical conductor which is a part of a circle with radius d. The metal rod and the circular electrical conductor is a closed...

Homework Statement In the following diagram, the brown metallic conductor rod is given a slight push to the left. The black lines are all conducting wires, with the entire setup placed in a perpendicular B-field. Ignore friction. What will happen? 1) The rod slowly come to a stop? 2) The rod...

Homework Statement Parallel plate capacitor with circular plates with radius of 26mm and a plate separation of 6mm. A sinusiodal potential difference is applied across the capacitors plates with Vmax = 170V at a frequency of 60Hz. 170sin(2*pi*60Hz*t) Homework Equations V = ∫E∙dl = El (l...

Homework Statement http://img834.imageshack.us/img834/5598/46421047.th.png Uploaded with ImageShack.usThe Attempt at a Solution I think this problem is deeper than it looks. Here is my FBD http://img291.imageshack.us/img291/69/31024385.th.png Uploaded with ImageShack.us So I am assuming...

Homework Statement Two long horizontal straight parallel wires are 3.18 cm apart and each carries a current of 9.25 A in the directions shown in the above figure. What is the magnitude of the B-field at point P, which is at a perpendicular distance of 2.25 cm from both wires? Homework...

I have what I thought should be a relatively simple problem, but a quick trip around the Google makes me wonder. It might be easier to just ask some real humans for once... I'm working with Hall Effect sensors and neodymium (NIB) magnets. I basically know the strength of my magnets, and the...

It's an intro plasma physics course, and already starting to get to me... I'm asked to derive an expression for the drift velocity of a particle in a constant uniform E-field, and a slowly time-varying B-field. I've looked at a few books to see if I can even find the final result, so I...

Homework Statement Show that the free energy of classical particles with no internal magnetic moment is always independent of magnetic field. Hint: Write down Z for N classical particles. Let the particles interact by U which depends only on the positions of the interacting particles. Show...

I read somewhere that Thomson (1897) concluded that the electron was not an EM wave because it bended in a magnetic field and that it had been proven that EM waves did not do this. Is this true?

1.Calculate the average E-Field and B-field produced by a laser with power 10W and radius 1mm 2.Not sure where to start with this one. Use equations of Flux perhaps? 3. So given the modest amount of infomation and the fact the question represents 1 mark, i assume the calculation is straight...

I'm looking to evaluate the magnetic field using Jefimenko's equations. There is two parts to it but I'm just looking at the first. The approximation is r>>r' where r' is localized about the origin. The Jefimenko's equation for the magnetic field (the first term that I'm having trouble with)...

Note this is more of a coursework theory question then a specific homework question. I am learning about E and B fields and electromagnetic waves. A common EM figure I find is the propagation of a photon where the E and B field propagate through space as seen in the following link...

Homework Statement Find the B-field between two ribbons with the current flowing in opposite directions on each. Homework Equations Biot-Savart equation The Attempt at a Solution In attempting to solve this I have found the B-field due to an infinite wire is B=...

Two long horizontal straight parallel wires are 28.28 cm apart and each carries a current of 2.2 A in the same direction, namely, due south. What is the B-field at a point that is a perpendicular distance of 23 cm from both wires? Answer in microtesla. B= (u0*I)/(2Pi*r) u0= 4Pi*10^-7=...

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...

Homework Statement What is the y component of the magnetic field at point O at time 0.227*E-16 s? Given: Frequency: 2.20*E16 Hz Max value of B-field: 4.00*E-8T when t = 0 at point O Homework Equations I think the following two equations could potentially be applied to the problem: B =...

Does the gravitomagnetic B-field (from the GEM equations) have units of frequency (1/s)? And if so, what exactly does the B field describe? I guess what I'm really trying to find out is whether the B field around say a rotating spherical object describes the rate of frame dragging, or does...

Homework Statement E = 20 cos(\omegat-50x) \widehat{y} find H in free space? Homework Equations I used (\nabla X E ) = -dB/dt , and then integrated that expression with respect to t , for some reason I am getting an incorrect answer ?! The Attempt at a Solution the correct answer is H =...

Homework Statement A proton that is accelerated from rest through a potential of 20.0 kV enters the velocity filter, consisting of a parallel-plate capacitor and a magnetic field, shown below. http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype61/prob09_velfilter.gif The E-field...

Homework Statement Suppose that the magnetic field in some region has the form B=kz\hat{x} (k constant). Find the force on a square loop (side a) , lying in the yz plane and centered at origin if it carries current I flowing counterclockwise, when you look down the x-axis. Homework...

a.) What happens to the force on a particle in a b field if the angle between velocity and the b field is 90 degrees? b.) and 0 degrees?

Homework Statement Determine the B field at a point P with distance d from centre of current ring radius r (d>r ie outside ring of current) but IN the Plane of ring (i.e off the axis) Homework Equations Biot savart: db=(u.I/4pi.r^2).dl.sinx u=mu, I=current, x=angle made with...

I am trying to calculate the E-field from a varying B-field. The B-field is from a current loop. \vec{B}(\vec{r},t)=\vec{B_{0}}(\vec{r})Sin(\omega t) where \vec{B_{0}}= http://www.netdenizen.com/emagnet/offaxis/iloopoffaxis.htm" Now since B is varying with time there should be an electric...

Homework Statement Consider an ideal cylindrical solenoid of length L and radius a=L/2 on which a thin wire has been wrapped a total of N turns. A steady current I flows through the wire. Assume the wires are wound so tightly that the solenoid can be thought of as a collection of N parallel...

Its been 15+ years since I have done any calcs like this and am very rusty, so even just a pointer in the right direction would be really appreciated... I need to calculate/estimate the magnitude/value (IF any!) of eddy currents that would/could be generated in an ultra high speed rotating...

Homework Statement A long, straight wire lies along the y-axis and carries a current I = 8.00 A in the -y-direction . In addition to the magnetic field due to the current in the wire, a uniform magnetic field with magnitude is in the +x-direction. What is the magnitude of the total...

Problem A one dimensional particle of mass m and charge q moves on a circle of radius R. A magnetic field pierces the circle. The total magnetic flux through the circle is \Phi = B \pi R^{2}. Determine the ground state energy E_{0} (\Phi) and show that it is periodic with period \Phi_{0} =...

Homework Statement The problem can be found here; http://www.physics.uprm.edu/~mark/courses/FISI3172_I2007/PracticeExamIII.pdf Homework Equations Ok, ok. I made some reaserch, and I found that the; radius of an ion orbit on a mass spectrometer = mv / qB where m = mass, v =...

given is: http://img340.imageshack.us/img340/6684/oplosqa0.jpg So if you have a question with a B-field you need any speed given from the particles who entering in this field. Who can I find this speed? Thanks.

Hi! When a charge/current moves in a closed loop, a magnetic moment is generated. Is there any formula for connecting the magnetic moment to E-field and B-field? Patrick

spin 1/2 in B-field polarization direction?? Homework Statement A spin 1/2 particle with magnetic momnet mu=mnot*sigma is placed in uniform B-field, where the magnetic field is pointing in (theta,phi) direction in spherical coordinates At t=0, the particle is in the (1 0) state...

Hello all, Im trying to do this magnetic field lab and am having trouble with the very last question. It goes: "Assuming the equation (Ampere's Law: B=unI) applies for the solenoid, calculate the value and uncertainty of u (permeability of free space) using the graph of B vs. n. In this...

A circular loop with radius a = 0.25 m and N = 17 turns lies in the plane of the page (x-y plane). The wire used in constructing the loop has a resistance per unit length of dR/dl = 0.11 W/m. A spatially uniform magnetic field points in the -z direction (into the page). In the interval...

A student wishes to light a lamp rated 12V, yet he has only a 2V rms a.c supply with variable frequency. So he attempts to step up the voltage by means of a transformer. Given Ns:Np = 6:1, resistance in the primary circuit is 70 ohm, inductance of primary coil is 0.3H, frequency f is 50Hz a.)...

Imagine I take a pair of helmholtz coils and apply a DC current, modulated by a much smaller AC current so that the B-field between the coils varies sinusoidally about some fixed value. Will the AC component of B be in phase with the AC voltage, or the AC current?

A 7.2 cm diameter loop of wire is initially oriented perpendicular to a 1.3 T magnetic field. It is rotated so that its plane is parallel to the field direction in .20 s. What is the average induced emf in the loop? A = πr2 A = π*.001 = .004 m ФB = BA = (1.3T)(.004m) = 5.2E-3 Wb...

Howdy I'm having a ton of trouble with this question Basically I have a spiral coil running around the z-axis with radius 'a' height '2b' and pitch 'c'. The point (x,y,z) = (a,0,0) is on the spiral and n = 2b/c (that's the number of turns on the spiral). There's a steady current running...

If there's a loop exiting a B-field, where half of it is in the b-field and half of it is out. How would a potential difference be found in the wire? I said that V = BLv, (where L is the height of the loop, disregarding the width) and found V to be 3v. Although, there is one resistor on the...

How is potential difference found between two plates in a B-field? Any help is greatly appreciated.