Magnetism Definition and 952 Threads

Homework Statement a single square loop of high resistivity wire ( rho = 10^-6 ohm-meters) is placed in a constant magnetic field B of 0.3 Teslas and oriented so that the axis of rotation of the loop is perpendicular to B and in the plane of the loop. the loop rotates with an angular frequency...

Hi, While studying my E&M course I asked my myself the question: why do the sides of magnets of same pole repel and opposites poles attract? I just can't manage to answer that question. I'm sure there is a very simple answer... Can someone help me with this?

Point charges w/velocity have a magnetic field. How does an uncharged capacitor slow the point charges to zero velocity? Shouldn't elastic collisions with other point charges or atoms predominate, followed by inelastic collisions that convert point charge kinetic energy to thermal energy?

ive been hearing about this course in the community college i attend and from what I've heard is that this is the hardest lower division physics course that most people take. I am a civil engineering major and the people I've talked to are also engineering majors. any advice for those who have...

Homework Statement An electron has a velocity of 2.00x10^6 m/s perpendicular to a magnetic field of 3.3T. What force does the electron experience? Homework Equations The Attempt at a Solution F=qvB q=1.6x10^-19 (the charge of an electron) V=2.00x10^6 B=3.3...

Hi, I have a research question focusing on the historical development of the telephone. However, I have to write it with emphasis it's dependence principles of magnetism. So far, I have not found anything to relate the two topics. I also must include 1. a reference to at least one person who...

There's a principle that the electric field is stronger/more intense at the most pointed parts of a charged, non-uniform conductor. Does this principle also apply to magnets? I.e. if we have a non-uniform magnet, is the magnetism density (sorry for the lack of a more scientific word) greater...

Hello I have these two questions on electricity and magnetism which I don't understand very well these are: (Q1) If a closed surface encloses no charge, and electric field lines cross the surface. (Q2) Under what conditions can coloumb's law be used to find the electric field strength...

Like the earth, do other planets have magnetism?

http://psi.phys.wits.ac.za/teaching/Connell/phys284/2005/lecture-01/lecture_01/node13.html But what about induced current? My brain is full now, can't think.hehe: http://www.physics.uoguelph.ca/applets/Intro_physics/kisalev/java/indcur/index.html

If you take a screwdriver for example, and hit it a few times near the tip with a hammer or something hard; why does the screwdriver become magnetic? I was shown someone doing this, and shortly afterwards it was able to attract nails or screws around.

suppose you have a solenoid with hollow core connected to a galvanometer. On one side you have a S-N magnet (ie. the N pole is nearer to the solenoid). On the other side you have a N-S magnet( ie. S pole is nearer to solenoid). ie. [S - N] [Solenoid] [N - S] Both magnets are...

Does conservation of energy apply to magnetism? and Do magnets ever "wear" out. Do they ever lose their magnetism?

Homework Statement http://img231.imageshack.us/img231/5296/physicspd2.jpg Homework Equations none really. The Attempt at a Solution 1. I think that the two outside magnets would attach to the middle one and their eventual velocities and accelerations would equal 0 but that...

Magnetism! Help! can someone please explain the hand rule thing to me...i am dead lost when teacher is explaining it. All i know is that your thumb is N and the bottom of your hand is S...please help!

Homework Statement Two infinitely-long lines of charge run parallel to the z-axis. One has a positive uniform charge per unit length, [lambda]>0, and goes through the x y plane at x=0, y=d/2. The other has a negative uniform charge per unit length, -[lambda], and goes through x=0, y=-d/2...

Homework Statement a) You have two electrically neutral metal cylinders that exert strong attractive forces on each other. You have no other metal objects. Can you determine if both of the cylinders are magnets, or if one is a magnet and the other just a piece of iron? If so, how? If not, why...

http://sci-toys.com/attention/2007/05/einstein-points-way.html According to the author, magnetism is an implication of Einstein's relativity. Is it true? His arguments sound reasonable, though.

Can anyone check if I answered these questions correctly? Thanks a bunch! 1. The N pole of a bar magnet is pointed in along the axis of a horizontal, continuous coil of wire. When the magnet is quickly roated about a vertical axis until the opposite end of the madnet points into the coil...

I will probably be taking both CM I/II and E&M I/II before I graduate, but I'm wondering is it a bad idea to take E&M before taking CM? I don't think I can take both at the same time this coming year so I have to pick just one.

Homework Statement Purcell 3.3: In the field of a point charge over a plane, if you follow a field line that starts at the point charge in a horizontal direction, that is, parallel to the plane, where does it meet the surface of the conductor? Homework Equations The problem 'hint' is...

Light is the result of an electron moving to a lower energy state, giving off a photon a particular wavelength in the electromagnetic spectrum. Current is the movement of electrons which induces a magnetic field. A magnetic field can create current by moving charges. Is there a relation...

Say we have two electromagnet A and B a light year apart from each other. Someone turn on A and a magnetic field is created and propagate at c toward B. It takes a year for the mag field from A to arrive B, B is turned on just before A's field arrive. B's field made to be opposite from A and...

Hello. I am a new poster; I hope I am correctly observing the forum rules. I have a slightly philosophical question about magnetism. It seems to be very simple, but I am struggling to find myself a convincing answer. Here it is: - - - If you place a piece of magnetically susceptible...

Hopefully I am posting in the correct forum, but was reading through Cahill's 'Physics 12 for Western Australia' (2nd Edition) and reached chapter 3, regarding magnets and electricity. There was one paragraph which confused me, and seeing as the school year has not started yet, there is no...

Hi everyone! As I understand it, magnetism can be explained by special relativity when charges are moving - length contraction in different frames of reference leads to coulomb forces between the charges in these frames. But how does magnetism in a permanent magnet arise? Are there...

I'm completely confused because of a previous post on Newtons second law and magnetism! Can someone help me to find a connecting or a superior explanation for the magnetic field as it appears in its the 2 forms? 1.) In some solid due to spin alignment. 2a.) In a cirque current flow. 2b.)...

Homework Statement A high voltage power line carries a current of 110 A at a location where the Earth's magnetic field has a magnitude of .59 G and points to the north, 72 degrees below the horizontal. find the direction and magnitude of the magnetic force exerted on a 250-m lengh of wire if...

[SOLVED] Magnetism question Homework Statement A proton, a deuteron and an alpha particle with the same kinetic energies enter a region of uniform magnetic field, moving at right angles to B. Compare the radii of their circular paths.Homework Equations v = qBR / m The Attempt at a Solution...

Question: http://web.ics.purdue.edu/~yeo/phys1.jpg Formula: (Gauss's Law for Magnetism) Line integral of[B dot nhat(perpendicular unit vector) * deltaA] = 0 The Attempt at a Solution So, if there is a bar magnet inside, the side arrows are pointing in the wrong direction, so I ruled...

Hi everyone, first post. I am curious to know how magnetism from a solar body differs at its equator. does it differ at all? Since the North and South are theoretically maximum points in the magnetic loop, at the very equator of their relationship this would be an inverse of that maximum...

I'm a freshman in college with only AP physics knowledge, and I'm curious about many aspects of physics. One of the thing that sparks my interest is magnetism and I was wondering if it is possible to have magnetic or electromagnetic force exerted on non-metals (maybe even noble gases). It would...

On these problems all i can figure out is which formula to use..after that i am completely lost..I don't really like physics, the whole pick the right formula for the given problem is too confusing for me... Problem 1) I think its Fmag= q*velocity*B*sin(theta) or would it be Fmag=...

1. wHAT ARE ENERGY SOURCES AND POWER STATIONS? 2.WHO WAS THE FIRST PERSON TO DISCOVER THE ENERGY SOURCE? 3.WHO BUILT THE FIRST POWER STATION AND WHO DISIGNED IT? 4.WHY DID HE/SHE DECIDED TO BUILD THAT POWER STATION THERE? 5.WHAT DO SOUTH AFRICANS GAIN FROM THAT POWER STATION? 6.IS THERE...

In magnetism , mH = F, where m = pole strength ; H= magnetic field intensity ; and F = Force. F = [ MLT^{}-2] Proof that dimension of mH = [MLT^{}-2]

Homework Statement A magnetic field has these components: x: B = 0.056 T y: B = 0.046 T The particle has a charge of +6.5e-5 C, has a velocity of 2.6e3 m/s, and is moving along the z axis. Questions: 1: What's the magnitude of the net magnetic force on the particle? 2: What's...

Hello, this is my first post here. I'm building an electromagnet as part of a larger experiment in my lab. My magnet needs to move a magnetic thread made with a paramagnetic substance. This string just barely responds to strong magnetic fields (tested it with standard speaker magnets). The...

Hi Does anyone have a link to a proof that magnetism is a result of relativistic effects on a moving charge? I am sure that I have seen one but I can't find it. Thanks John

I have always wondered, what causes magnetism? I have only high school level physics at the moment, so I do not know the "whys". WHY do two opposite magnetic poles attract, and likes repel?? And where does a magnetic get its energy to say, cling to a fridge?! Or is there something...

folks, in higher secondary books i came across magnet's length that is bar magnet's length is given as " 2l" that is 2 multiplied by l. my question is " why the length is not referred as 'l' the usual way of referring length. please clarify in layman terms. thanks in advance logesh aravindan

What is magnetism exactly? I understand it is a portion of the electromagnetic force of a moving charge directed to where it used to be.

hi, i have a question that i don't really get, so anyone to help? Explain, using the domain theory , why heating or dropping a magnet can cause it to lose its magnetization? thanks to anyone who would help

Homework Statement One method for determing masses of heavy ions involves timing their orbital period in a known magnetic field. What is the mass of a singly charged ion that makes 7.0 revolutions in 1.3 x 10^-3 seconds in a 4.5 x 10^-2 T field. a) 2.1x10^-25 kg b) 1.3x10^-24 kg c)...

Homework Statement Question 1- Magnetized Ship You are standing on a shore beside a shimmering blue sea. You will go on a sea expedition to Magnesia and claim the lost treasure of Magnesia. Magnesia is an island which lies near the Antarctica. The only way to get there is by sea. The ship...

Temperature effect on magnetism. The curie point for mild steel is about 750deg C. Before this temp it is ferromagnetic and after that temp its paramagnetic i think. But my question is does the magnet permiabilty of the mild steel gradualy reduce as it gets hotter up to that temp? If...

I always have found magnetism hard to understand. Maybe even harder to understand than quantum mechancis? This could be spurred from the fact that my command of vector analysis isn't great. How do I develop an intuition for magnetism?

What causes the attraction or repulsion between magnetic poles? Answer this from the perspective of an electron. There are two kinds of electric charges: positive and negative. • Charges exert forces on other charges at a distance. • The force is stronger when the charges are closer...

I know that electric fields generate magnetic fields (when you put a compass next to a wire that has current in it the needle moves indicating that a mag. field is present). I know that changing magnetic fields can generate electric fields or induced emf. What does electromagnetic waves...

Homework Statement A long straight conductor carries a current I.Determine force per unit length of the conductor when it is placed in a unifrom magnetic field B. Homework Equations The Attempt at a Solution I got BI sin(theta) where theta is the angle between wire and the B...

Hey everyone, I have a few questions. What is the link between electricity and magnetism? Why would moving electrons(current) create a magnetic field? Why does a moving magnetic field induce a current in a conductor? Thanks for responces.