Magnetism Definition and 949 Threads

Hi! Can anyone please tell me where this equation was derived from? This equation is used to get the magnetic field (B). I is current and r is the distance. And I think I understand the Meu. And yet I have no idea where the 2pi came from. I looked in my textbook, internet and asked friends...

Suppose an electron orbits a proton at a distance of 'r' with speed 'v'. How could i determine the magnitude of the magnetic field at the location of the proton? I thought it would make sense to use The Biot-Savart Law, but i don't know where to begin: dB = \frac{\mu_o}{4\pi} \frac{I ds x...

Suppose I use the direction of my hand to be velocity, the curling of my fingers to be the magnetic field, and my thumb to be the magnetic force. 1.) Then, if a positive object is moving North, and the magnetic field is NE, where is the resultant force? 2.) How about the Earth's magnetic...

I am trying to answer all the odd problems at the end of the chapter and I can't seem to get one of them. A long, current-carrying wire is oriented vertically; next to it is drawn a square whoe area lies in the same plane as the wire. Using the distances indicated, find the magnetic flux...

So these Earth's magnetism is supposedly produced inside these generator-like chambers inside of which various chemicals are mixing to form some sort of giant electromagnet, in theory, right? But whether this is or isn't true, where does magnetism come from at its root? Do photons have...

I place a magnet near a piece of iron. The iron bit accelerates across the floor towards the magnet. The magnet has done work. Energy has been expended. Where did this energy come from? This energy seems inexhaustible. Why isn't it used up?

GR explains how gravity works. Is there a similar explanation for magnetism. Maxwell showed that magnetism and electricity are two sides of the same coin. And I understand that electricity is a flow of electrons. Can that help me understand magnetism?

Do strong magnetic fields have any negative effects on the human body? Also, where can I find information regarding this subject?

Electricity and Magnetism urgent!pls! An infinite long line of charge of constant charge density a is located near the line AB which carries uniform charges with charge density b. Suppose both two lines are in the same plane, calculate the electrostatic force exerted on the line AB. i don't...

Electricity and Magnetism urgent!help! 11. Electric charge is distributed uniformly along each side of a square. Each side of the square has length a. Two adjacent sides have positive charge with total charge +Q on each. (i) If the other two sides have negative charge with total charge –Q on...

why adding copper to nickel result in reduced magnetism of nickel? :confused:

(law of conservation of energy!) apply to electricity & magnetism... ok guys... first look at the PICTURE. (now imagine) suppose i put SUCH CYLINDRICAL magnet in zero-gravity, perfect vaccum. Then say, i rotate the cylindrical magnet about its axis. a). what should happen? ->well, there...

silicon atom has 14 electrons with 2 unpaired electrons in 3p orbital. why silicon is not magnetic? :confused:

hi i have a few general questions on the right hand rule, 1. if a charged particle enters a magnetic field going from bottom left to top right at an angle of 45 degrees, and the direction of the current is vertically up how do we determine the force using the right hand rule? 2. a wire which...

Maybe this is more of a chemisty question but I have found that stainless steel is not magnetic. I can only reason that this would be if the Fe (iron) inside the steel is actually bonded with the other components of steel thus making the 3d spins useless to become aligned. i did a search and...

"scientists can produce magnets as strong as 40,000 Gauss" now when Ill come to calculate the force between two of these magnets, I will have to know their "strength". according to the 40K Gauss, what will be this strength? In other words, what does 40,000Gauss tell me about its strength...

I am wondering if a magnetic force will deviate different mass amounts of the same material through the same path as each other just like gravity does to different mass amounts of any material? Does anyone know? Has this been tested?

1) A horizontal metal rod of 1.5m long is aligned in and East-West direction and dropped from rest from the top of a high building. Calculate the e.m.f. induced across the falling rod 2.5s after release. The horizontal component of Earths magnetic field is 2x10^5 T. Surely you need the area...

I read on some physics website somewhere (I forgot which one) that a magnetic field around a bar magnet exists because there is a tiny probability that some electrons exist outside the bar magnet and when they do they emit virtual photons that can interact with other things to create the...

We are students in a scientific research project studying the physics of magnetism. We have made some strides but are looking to start a good brainstorming session into the physics of magnetism. All is welcome to join at http://projecthome2010.proboards2.com/index.cgi?board=general

As a diver, I'm constantly struggling with accurate compass readings. How much ferrous material at what distance would affect a compass? For example, would fifty pounds of steel two feet away affect the needle? If the needle of a compass is magnetic, will the needles on two compii affect...

Hi there, I have just set up / taken measurements from an "Einstein de Haas" experiment I set up, but there were a couple of weird effects I cannot explain nor figure out. FWIW, I am competing in the "International Young Physicists' Tournament" in Switzerland this July - should be a great...

Ok i was wondering something. If you send some light through a polarizer... how does the magnetism get through? I know you never find E without its M... but if you can block light with a polarizer (the light coming at a different angle), why would the magnetic part come out with the light that...

My teacher recently gave me a task of relating magnetic forces to a beam of chraged particles moving in a straight line. To aid us in this, she also set up a guideline question, displayed below: The diagram below shows a beam of charged particles moving in a straight line with speed v. Each...

A proton moves in a circular path perpendicular to a 1.15-T magnetic field. The radius of its path is 8.40 mm. Calculate the energy of the proton in eV. So, I calculated the velocity with: qvB = \frac{mv^2}{r} (1.60 \times 10^-19)(1.15) = \frac{(6.27 \times 10^-27)v}{0.0084} v = 2.47...

I'm confused if I am using the right equations to solve this problem. P: A singly charged Li^7 ion has a mass of 1.16x10^-26kg. It is accelerated through a potential difference of 500 Volts and then enters a magnetic field of 0.4 Teslas, moving perpendicular to the field. What is the radius...

A wire 36m long carries a current of 22 A from east to west. If the maximum magnetic force on the wire at this point is downward (toward the Earth) and has a magnitude of 4.0E-2N, find the magnitude and direction of the magnetic field at this location. I have no clue where to start. What...

Which is the correct equation for Magnetic Reluctance ? R = Reluctance l = Length A = Area \mu = Magnetic Permeability of the material \mu_0 = Magnetic Permeability of free space ( 4\pi \times 10^- ^7 tesla/ampere turn) R = \frac {l} {\mu A} as stated on Wikipedia or R =...

Could someone help me with this problem? I don't really know how to do it.. http://www.webpost.net/bl/bluesoda025/magnetism.gif What is the magnitude and direction of force acting on wire 1 due to the magnetic field produced by wire 2?

Hi. I'm having some trouble with this problem: An electron accelerated from rest through potential difference 1.6 kV enters the gap between two parallel plates having separation 20.0 mm and potential difference 120 V. The lower plate is at the lower potential. Neglect fringing and assume...

Hi, I'm new to this site. Anyway, I am studying for the MCAT right now and the physical science review that I have been doing has gone pretty well, I just have a few questions about comparisons that can be made between movement of electrons and movement of solid objects. 1) What is the...

1. Is Ampère's law (\nabla \times \mathbf{B} = \mu _0 \mathbf{J}) consistent with the general rule that divergence-of-curl is always zero? Show that Ampère's law cannot be valid, in general, outside magnetostatics. Is there any such "defect" in the other three Maxwell equations? I'm not...

A horizontal rod is moved northward at a constant velocity throough a magnetic field that points straight down. Which statement is true? a) The West end of the rod is at higher potential than the east end. b) The East end of the rod is at higher potential than the West end. c) The top...

Does magnetism have any affect on gravity?

I was wondering if anyone could help me with a question. I am a long time knife collector, and after a block of steel is formed it gets demagnetized...after the steel block is then ground into shape and finally sharpened on a grinder, it some how becomes slighty magnetic. Knife makers say its...

Let's say you have two magnets of the same magnitude facing each other, North facing South. At a certain distance, with let's say and iron filling placed at a certain spot, is there a spot where the net magnetic force exerted on the filling will be zero?

Problem 1: A proton is shot with a speed of 8x10^6 m/s at 30 degrees to an x-directed field with B=.15 T. Completely describe the path followed by the proton. Describe the path in words and also give the radius, the period, and the pitch. The proton is going to take a spiral - screwdriver...

I'm having trouble starting this problem... I'm pretty sure I'll be able to figure it out if I can just get past the first question. I scanned the sheet because I'm lazy and I thought that you'd be able to understand the problem better that way anyways. So if someone could just point me in...

Answered Finished! Thanks to all that helped out.

electrons and magnetism. - need help. An electron moves with velocity v = (4.0i – 6.0ij) x 104 m/s in a magnetic field B= (-0.80i + 0.60j) T. Determine the magnitude and direction of the force on the electron. F=ma: qvB=m*v^2/r : r= mv/qB r = (9.1E^-31kg * (4.0i – 6.0ij) x 104 m/s) /...

Hey this is more of a general question than a problem... What happens to a human body after it has reached its magnetic exposure limit (.2 Telsa)? Does the magnetism pull iron out of the blood stream, or cause any severe or fatal health issues? Something must happen, or else there would be no...

First off I am sorry for asking this question , as I am sure I am way off base. I collect high end pocket knives and some of the blades have become a little magnetized; so i found a demagnetizer that uses NdFeB30 magnets, which are rare earth? MY question is this, if i rub the demagnetiser over...

I am currently working on a problem that states... An electron experiences the greatest force as it travels 2.0x10^6 m/s in a magnetic field when it is moving southward. The force is upward and of magnitude 2.3x10^-12 N. What is the magnitude and direction of the magnetic field? I started...

Here it is... The diagram shows a current balance loop that includes the conductor where l1 and l2 represent the segments of its length. You have been asked to do an experiment that anazlyzes the relationship between magnetic field strength and current in a solenoid by plotting a graph...

Hello I've run into quite a few crappy diagram questions on my Homework assignment due tomorrow. All of the questions are from my school's (Central High Sedgewick) webpage. The teacher thought she'd be sly and hide the answers on some of these questions. The webpage is this...

Hi my grade 11 physics class is on its final unit (Electricity and Magnetism) and I am a little lost... So far we are doing Charge and Voltage (we learned the formulas)... and we're expected to know that circuit diagram stuff and Ohm's Law? lol a bunch of stuff we were suppose to learn in grade...

Hello, I was wondering if you guys know any websites/ free books/ any other ressource about physics electricity and magnetism, since this is my next class and I want to try to read about it before starting. I have download an e-book from the sticky, but I'd like other sources. feel free to...

I have a huge problem to work out.. but first, i can't find the equations for (1) electrostatic potential of the center of a square (a charged particle at each vertice) and (2) the magnitude of electric field at the center of the same square. These are both questions to two...

HELP - Magnetism Physics Problem! The problem says: A long piece of wire with a mass of .100 kg and a total length of 4.00m is used to make a square coil with a side of 0.100 m. The coil is hinged along a horizontal side, carries a 3.40-A current, and is placed in a vertical magnetic field...

ok, sorry if I'm posting this in the wrong place but move it to the right one and whateve. Anyway, I may have no idea why I'm talking about, using incosistent models or something, in which case I would appreciate it if you told me. Okay, if opposite charges attract, why not different quantum...