Magnetic fields Definition and 674 Threads

Homework Statement The unit of magnetic flux is named for Wilhelm Weber. A practical-size unit of magnetic field is named for Johann Karl Friedrich Gauss. Along with their individual accomplishments, Weber and Gauss built a telegraph in 1833 that consisted of a battery and switch, at one end...

Homework Statement The diagram shows the magnetic field between like magnetic poles Homework Equations Point C is the exact middle of the region between the poles. Explain why the strength of the magnetic field at point C is zero? The Attempt at a Solution The like poles repel each...

Hello all, thanks for reading. I'm in the process of designing a machine that will move a hall effect sensor in 3 dimensions through a magnetic field and record readings. Before I started the design however, I wanted to see if there would be huge problems in how I envision this machine...

Can an electromagnetic wave be deflected by electric or magnetic field.

It is well known that all sorts of systems tend towards minimal potential energy. I was wondering if this applies to static electric fields also, i.e. is an electric field such that it's energy integrated over all space is minimal? For example if we have a bounded source free region and if the...

when we say , electron acts like a wave ,does we mean to say that it produces electric and magnetic field or em waves varying with distance and time

Hi. I am researching magnetic fields and getting no where. I am writing a computer programs to calculate Magnetic force between 2 magnets that can act both + to + and + to -. Given the movement of the magnets, the program will be calculating minute movements and compensating for changes in...

What impact will a extremely high frequency of ultrasound have on a electromagnet? Will the magnetic field also oscillate at that frequency? What about a conductive wire transmitting electrical current? Will ultrasound on the wire cause the magnetic field to oscillate?

Hello all, I am in need of understanding of magnetic fields. More specifically i was wondering exactly why there is a magnetic field around a wire with current moving through it. Where i am going with this is.. if i had plasma contained, and i managed to get it moving in the container, would...

Homework Statement There is a magnetic field given by the equation \overrightarrow{B}=B_{0} \hat{x} \sin\left(2\pi z/L\right). If there is a 10^7 eV electron going in the \hat{z} direction (moving at a relativistic velocity), a mag. field strength of 0.1T, and a mag. period of 0.01m, what...

Hi, just reviewing some of my physics material, and realized I had a question that has never been answered for me. I know that charged particles, traveling parallel to a magnetic field, feel no force either forwards or backwards, but feel a force perpendicular that causes them to spiral...

Two infinite sheets of current flow parallel to the y-z plane as shown. The sheets are equally spaced from the origin by xo = 7.5 cm. Each sheet consists of an infinite array of wires with a density n = 19 wires/cm. Each wire in the left sheet carries a current I1 = 3.5 A in the negative...

I wanted to know if there is a mathematical model to know the force with which a source of a magnetic field attracts or repels another source of magnetic field. For example, the mathematical model for the electrostatic force a charged particle exerts over another charged particle is: F =...

Hello everyone, I'm a photographer and am developing a project in which I'm needing some help. I went to some engineers friends first but they told me Physicians would be the ones who would have the answers I need. I'd like to know how can I interfere in the way my camera's sensor...

Where can I find a picture of the magnetic field lines produced by a charged particle moving near the speed of light? Is there a formula for the strength of B and direction of field lines as v --> c? Does this equation reduce to Ampere's right hand rule for a moving charge's ability to create...

Homework Statement A 1.0 m piece of wire is coiled into 200 loops and attached to a voltage source as shown. A. Find the strength of the magnetic field inside the coil if V = 100 V and R = 40 Ω. B. Which direction does the magnetic field point? C. The wire is then uncoiled and re-wrapped so...

A negative particle is moving in a uniform magnetic field pointing in the negative k direction. The force on the particle is -i and j. Find the x and y components of velocity. (I left out the numerical data in the question). I used F=q*v*B and in order to find the x component I used the F in the...

Would a magnetic field have any effect on the dielectric breakdown of insulators? For example, the dielectric breakdown of air is 3 Mega volts per meter at a gap of one meter; if you applied a magnetic field to that breakdown, would it help guide the electrons along the path and therefore reduce...

Homework Statement Heres the question: http://imgur.com/aFJFxLa Homework Equations B = μ0/2∏r The Attempt at a Solution μ0 = 4∏*10^-7 Magnetic field = μ0/2∏r + μ0/2∏r = μ0/2∏(0.05) + μ0/2∏(0.05) = 4*10^-5 The answer is 24*10^-6 T. I need...

1. Homework Statement [/b] A solid cylindrical conducting shell of inner radius a = 4.9 cm and outer radius b = 6.1 cm has its axis aligned with the z-axis as shown. It carries a uniformly distributed current I2 = 7.4 A in the positive z-direction. An inifinte conducting wire is located along...

Homework Statement A current of constant density, J0, flows through a very long cylindrical conducting shell with inner radius a and outer radius b. What is the magnetic field in the regions r < a, a < r < b, and r > b? (Use any variable or symbol stated above along with the following as...

For a magnetic fields lab I am asked to graph the data and from there, use the slope to find a certain value. For one of them, I am asked to plot the current (x) vs the magnetic field (y). The slope is supposed to give me a value, I have the slope, no clue what the value would represent...

Homework Statement Two infinite sheets of current flow parallel to the y-z plane as shown. The sheets are equally spaced from the origin by xo = 4.2 cm. Each sheet consists of an infinite array of wires with a density n = 16 wires/cm. Each wire in the left sheet carries a current I1 = 2.3 A in...

Hey Pf.. I am trying to understand Lenz's law, but somehow it doesn't make sense. In my book there is some checkpoints execise to test wheather you've understood what you read about, one those checkpoints looks like this. http://snag.gy/NCNLh.jpg I do understand why the current in...

Homework Statement A particle of mass m and charge -q moves in a circular orbit of radius R about a fixed charge Q. The angular frequency for the orbit is given by \omega_0^2 = \frac{qQ}{4 \pi \epsilon_0 m R^3} A uniform magnetic field of magnitude B in a direction perpendicular to the plane...

Homework Statement An ion of mass m and charge q is accelerated from rest through a voltage of ΔV. It then enters a magnetic field. Determine the mass of the ion in terms of the measurable quantities: q, ΔV, (B^→) , and x. Homework Equations The Attempt at a Solution m =...

We know that a direct current generates a magnetic field which surrounds the wire in circular patterns (right-hand rule). However when alternating current runs through a wire, no actual electrons are transported from one end to the other but rather they "vibrate" so to speak and transmit this...

Momentum and magnetic fields are both vector quantities. If two bodies with the precise mass and speed collide head on (θ = 0), then momentum is conserved (they come to a complete stop) and energy is conserved (the kinetic energy is changed to other forms). What then happens in the case of...

A gravitational field and a magnetic field both decrease in strength at the distance squared. They are two totally different forces so why the correlation?

Homework Statement z+ up with E field, y to the right, x out of the page with B field particle released from rest at (0,0,0) with only initial y velocity y=(E/B)t or initial y=(E/2B)t Homework Equations can you suggest a good differential equations text...

With my term-end examinations fast-approaching, I sat down to revise my entire senior year physics syllabus. As I was reading through electromagnetic induction, I found myself in the same state of utter confusion that I found myself in when I first studied about Lenz's Law and Eddy Currents. But...

One component of a magnetic field has a magnitude of 0.0266 T and points along the +x axis, while the other component has a magnitude of 0.0648 T and points along the -y axis. A particle carrying a charge of +2.96 × 10-5 C is moving along the +z axis at a speed of 4.71 × 103 m/s. (a) Find the...

Homework Statement The Lagrange method does work for some velocity dependent Lagrangian. A very important case is a charged particle moving in a magnetic field. The magnetic field can be represented as a "curl" of a vector potential ∇B = ∇xA . A uniform magnetic field B0 corresponds to a vector...

Hi, A current carrying wire creates a magnetic field around it, as shown here: http://courses.ae.utexas.edu/ase463q/design_pages/fall02/wavelet/3_sour8.gif As far as I am aware this usually doesn’t cause a power loss. Even if there is a flux on a nearby conductor there will be no power loss...

Homework Statement I have a coaxial cable with current density Jo in the center, with radius a, going in -z_hat direction. This generates a magnetic field. The outside of the cable, radius c, also carries a current density Jout going in the +z_hat direction. This generates its own magnetic...

Homework Statement Consider two infinitely long cylinders with radius a and b and currents: J = (Jo r)/a for r less than a -Jo for a less than r less than b Find the magnetic field in 1) r less than a 2) a less than r less than b 3) r greater than bHomework Equations The...

If we set up an experiment in a chamber with distinct perpendicular oscillating i) electric and ii) magnetic fields, cycling at a frequency representative of visible light, will the chamber suddenly light up? If not, why?IH

At one instant, the electric and magnetic fields at one point of an electromagnetic wave are E = (210 + 320 − 40) V/m and B = B0(7.5 − 7.5 + a) μT. Find a and B0 E=cB The Attempt at a Solution So I found a using E dot product B = 0 and I got the value a=-20.625 and this is...

Homework Statement What will be the net magnetic field at a point, if two mutually perpendicular magnetic forces are acting on it? Homework Equations The Attempt at a Solution

I want to know what exactly is magnetic and electric field fringing and what is the cause of it?

I know that energy density of Electric and Magnetic Fields are (ε/2)*E2 and [1/(2μ)]B2 respectively. But I can't understand how we get those expressions. Would be really happy if you could clear my problem. Thanks a lot

Homework Statement The figure shows a zero-resistance rod sliding to the right on two zero-resistance rails separated by the distance L = 0.53 m. The rails are connected by a 10.9-Ω resistor, and the entire system is in a uniform magnetic field with a magnitude of 0.750 T. (a) Find...

In a capacitor, specifically a parallel plate capacitor, ideally we have that capacitance is a function of permittivity, separation, and plate area. Does permeability play any role? Is all the energy stored in the electric field? Please consider this in a charge static state and also when...

Why do magnetic fields only apply force to charges/currents that are perpendicular to the field? Does it have something to do with the orientation of the field created by the moving charge in relation to the field it is in?

what creates magnetic fields, magnetic poles or currents? are those theories equivalent mathematically? i read in Griffiths currents are the sole source of magnetic fields but in another book it said those theories are equivalent. has it been proved the theory of magnetic poles is wrong/ or is...

When i think of electromagnetic waves i think of a fast moving sphere of expanding or contracting fields,either magnetic or electrical depending on where its at in its cycle. So i guess I am picturing a single photon as a sphere. Is this a correct visualization?(i doubt it). If so, how does a...

I mean we really don't know what they are, right? We just know they can be positive or negative, north or south, but we really don't know why they exist. Will string theory give a definite answer to this? And also gravity. Will it confirm Einsteins theories?

say you have a very very long (or infinite) straight wire the carried a charge (glued to the wire) and the wire moves forward with speed v with respect to reference frame S, this creates a current, which according to the Biot Savart law creates a magnetic field. But in reference frame S'...

On the Origin of Solar and Stellar Magnetic Fields There is recent evidence that the solar magnetic cycle has been interrupted. This is a link to Livingston and Penn’s paper that notes the magnetic field strength of newly formed sunspots is decreasingly linearly. Specifically, why the...

Very strong magnets like neodymium can create a very powerful force! I wonder the amount of energy supplied when there created to be magnetized, in a sense don't they store energy and it is converted"demagnetized" over time? It came from the electricity used to create that magnetic field...