Magnet Definition and 912 Threads

If a permanent magnet rod enters a coil of wires at a certain speed will the permanent magnet slow down? I'm trying to build a generator of some sort. So i need to know is my logic sound. I'll give you scenario. Scenario: The permanent magnet slides into the coil at a speed of...

Hello, I am trying to calculate the magnitude of the attractive force between a cylindrical magnet and a sheet of iron. A bit of searching found some equations that can be used to calculate the force between two magnets but I could not find anything related to magnetic force on non...

When I placed the south end of a magnet on the right hand side of the green CRO spot (when timebase is off) facing towards the left hand side of the screen, I expected the spot to move downwards in accordance with the left hand rule, but instead it moves upwards. The spot also moves down when I...

Homework Statement Attached file shows the problem statement. The Attempt at a Solution I can do this problem easily. Problem is that there's just one step in my book's derivation that I don't understand. It sets ρ equal to the hypotenuse in the triangle and then says that: dl = ρ/sinθ...

Homework Statement this is an experiment from lab.. i have pendulum - mass (iron) hanging from a massless cord. under the mass there is a magnet. the movement of the pendulum is in a small angle. i repeat the experiment 5 times - each time in a different distance between the iron mass and...

Hey guys, sorry if this is wrong place to post this. If it is let me and I will try and find the right place. It was the only category where I saw something about energy and physics. This is also probably a basic question but I hope you don't mind me asking. Let's say you have an electro...

I would like to build an electro magnet capable of causing piano strings to vibrate without the strings being struck first. As long as the hammers are up, the strings would vibrate on their own accord. An E-bow, used by guitarist for the same purpose, will (sort of) work on a limited range on...

If I have a cylindrical permanent magnet and an electromagnet with both poles facing each other, would the permanent magnet attract to the soft-iron core of the electromagnet? Assuming both magnets are restricted on an axis and have +/- equal strength (~375lb pull force, 2" cross sectional...

Hi, I was browsing through many academic papers and could find little information of a simple solenoid with a permanent magnet in the core of the solenoid. Solving the field in a simple solenoid is very straight forward, but I was having difficulty understanding the interaction between the...

Hi All, I was wondering: for a given size and strength magnet sticking to a wall of a given material and surface area, does the thickness of the wall affect the strength of the attraction? What are the governing equations at play? I am trying to gain insight as to why or why not the...

Why is it that a radio wave or a microwave is not affected by a magnetic field from a electromagnet or bar magnet? I know they are self contained and so no outside force should effect them but that I can't get my head around. The idea I have is that since the Electromagnetic field is...

Hello everyone, I have a quick concept question for electrodynamics course. If a cylindrical magnet, axially magnetized, is rotated round its own central axis, axis of symmetry, will this create a rotating magnetic field in the vicinity of the magnet? what if the magnet was rotated around in...

This may be a dumb question but I am so lost and would appreciate any help! Is there a way to quantify the attractive force between a metallic object and a magnet? With numbers not qualitatively? I was under the impression that with a metallic object everything was microscopic so itd be...

I was wondering what it would be like if you had a permanent magnet inside the core of a material capable of obtaining the superconducting state. And you cooled it down so that it becomes a superconductor. Assuming it didn't explode; would it just condense the magnetic field into some...

I don't have a physics background but a debunking to this irrational thought process of mine would be much appreciated. I understand perpetual motion/energy is an old, dried, and silly topic, but I can't make sense of this, so thank you in advance for answering (and yes, it's to do with...

Hello all, I am interface designer that occasionally steps out and does some product/concept design. The last one I am working on is something that would require me to make a matrix of little electro magnets, and i am just starting to inform my self about all that. I loved electrical...

Dear Experts I have a 1.5 cm ring magnet, you know, the black color type of common low magnetic power magnet. I wrapped 5 turns of copper wire around it on one side and then wrapped 10 rounds of another copper wire around it . I connected 5v battery to the 2 ends of the primary coil which...

Hi, I'd like to use a millivoltmeter to research voltages induced from a basic ceramic magnet brushing by a conductor. So, I need to buy a millivolt meter. What voltage ranges will be required, and what read-rate should the millivolt meter have (in order for it to register the voltage in a...

I'd like to simulate the interaction between these magnetic balls on my computer. I suppose they are magnetic dipoles, how would I go about finding out the forces applying between 2 of them in a specific configuration ? Do I need to find the magnetic field and then apply the Lorentz force...

Dear all - I am new here so please be gentle :smile: I have searched the site for a few days but alas still have a few questions on something i am hoping to make...so with your kind help - here we go! I am looking to make a type of electromagnetic piston, basically i want to have an...

Homework Statement A soft iron ball is fixed a distance d above the pole of a rectangular dipole magnet which is permanently magnetized. What is the force the iron ball feels due to the magnetic field? The dimensions of the dipole magnet are a x a x b, where a < b Homework Equations...

NOTE : My Current question and source of debate is in post number 10. Lets say I have a square coil. I accelerate it in a direction such that it is perpendicular to a magnetic field directed into the page. As it enters the field and before it is completely in the field an...

Faraday's Law of Induction: EMF=-\frac{\partial \Phi}{\partial t} If two identical coil with same turns of wire and same dimension ( same cross section area in the middle), one has only air and the other has a magnet core. If the two placed in an uniform varying magnetic field, is there...

Homework Statement Place a coin vertically on a magnet. Incline the coin relative to the magnet and then release it. The coin may fall down onto the magnet or revert to its vertical position. Study and explain the coin’s motion. Just wanted to know, does anyone know any good sources i.e...

Homework Statement What is the force acting on a magnetic dipole that falls through a loop of wire? Any sort of answer, exact, approximate or a reference to a source that covers this would be excellent. I haven't been able to find much of anything on this problem. Homework Equations The...

Is it possible to estimate the magnetic field strength of a permanent magnet from the heaviest weight that the magnet can lift? The heaviest weight that can be lifted can be found by trial and error. Any comments or suggestions appreciated. inkpot

I apologize in advance if some of my answers don't quite make sense. I'm generally articulate, but not when it comes to physics I'm barely grasping. I did a lab and part of it was dropping a magnet through a coil, which produced a Voltage vs Time graph using LabPro. For trial 1 we had the N...

I'm currently playing with diamagnetic pyrolytic graphite and I have created a small portion of a track similar to this video I want to create a circular track for it travel on, but as rare Earth magnets are getting expensive I'm going to use thinner magnets that consequently have a weaker...

A experiment was conducted where we had an electromagnet and a magnet. Our aim was to see how close the electromagnetic would need to be before it would attract/repel the other magnet. We recorded the distance between the two magnets and the difference in mass of the normal magnet. The force...

It's a very important question in science. Are we alone in the universe? This is a question that should be handled like every other fundamental question, yet most people treat it like a novelty. If proof ever does surface it will be clouded by the enormous amount of hoaxes. When looking up...

Homework Statement The figure shows a wire that is connected to a power supply and suspended between the poles of a magnet. When the switch is closed, the wire deflects in the direction shown. Which of the dashed boxes A–D represents the position of the north magnetic pole? Homework...

For a rod magnet, how is the field inside the rod change if another piece of ferro magnetic material is being brought close to one end of the rod? Does the presence of ferro magnetic material increase the field strength inside the rod magnet?

Homework Statement A very strong magnet is suspended by a non-magnetic thread. A student forms a loop out of a wire attached to the Pasco 750 Interface as shown on the left. During a half second interval, the student moves the wire loop until it is below the magnet as show a) Describe...

Basically I was wondering if I was to place a magnet inside a tube sealed at both ends via two magnets (as the diagram shows) would the magnet keep on moving up and down or would it find a resting place. I think it would find a resting place but then I also thought there will also be gravity...

My question pertains to model trains. I use a magnet under my last car to activate computer commands via a reed switch. One locomotive has a speaker placed near the bottom and the magnet of the speaker activates the reed switch - which I don't want it to do. One thought to correct this is to...

What happens when you try to create a ring shaped magnet with a circular magnetisation. e.g. you take an unmagnetised steel ring, wind some copper wire around it, turn on the current for a few seconds and then remove the wire. Afterwards there should be a circular magnetic field inside the ring...

when you place a magnet into a solenoid with a ac current it will get demagnetised. So does this mean that the magnetic field will go into the magnet in the opposite direction of the magnet's own magnetic field? and disalign it. meaning will the magnetic field enter the magnet as though it is...

If I place a super magnet under the bottom of my water bottle, will it magnetize the water I drink everyday? Does anyone have any suggestions? Thanks in advance for any suggestions "After magnetization, the molecules line up in sequence “+-+-“ resulting in reduced surface tension, reduced...

When a current carrying wire is placed into a magnetic field there will be a force. Using Fleming's Left Hand rule. They also said that by increasing the number of turns of the coil will increase the force. But how does this increase the force? Also, by placing a soft iron rod inside the...

Homework Statement If I drop a magnet through a long tube of copper how would the EMF vary with time? Homework Equations The Attempt at a Solution When the magnet enters the copper tube some of the magnetic flux lines are being cut hence an EMF is induced in the copper coil If we...

A well known physics experiment is dropping a magnet through a vertical aluminum tube. The magnet slows noticably before passing completely through the tube. Electrical current is created in the aluminum tube thereby creating a magnet thereby creating an opposing magnetic flux to slow down the...

Hi when a good former explained a theory, I didn't understand this very well. So I'll check it out again. Sorry for the many posts my me and thanks! When a magnet is placed vertically to an iron wall it gets attracted.(meaning the north and south poles are in contact with the iron wall)...

Hi I am trying to understand the effect of dropping a magnet through a single coil of wire. If there is one turn of wire, connected to a resistor, and a magnet with known mass and flux density is dropped vertically through the coil, a current will be induced in the coil. The forces acting...

Homework Statement As the title states. Homework Equations B = μH outside B = -μH inside The Attempt at a Solution Derp.

Homework Statement A bar magnet is dropped through a horizontal coil as shown below. An EMF is induced in the coil with the resultant voltage shown on the graph. Explain the shape of the graph, in particular the differences in the regions marked as A, B and C. Homework Equations...

Hi, I am a high school student and I'm planning on entering a regional science fair with an experiment involving electrolytes, magnets, and electric currents. However, I don't understand electromagnetism well enough to fully understand everything that would be going on in the experiment, and as...

I have just received some ferrite grade Y30H-IA un-magnetized permanent magnets. I am looking to wind some copper around a section of pipe and place the ferrite inside in order to magnetize it. From what i have read the magnets should be anisotropic and to saturate the ferrite I will need only...

Apparently, that's how a lot of car speedometers work... but I don't understand how a rotating magnet inside a coil (or any conductive material, really) can induce a current in the coil. I can understand how pushing a magnet in and out through a coil can induce current, because Flux = Area...

Suppose I have a sphere of steel. Now suppose that I take this sphere and cut it into hundreds of solid-angle pieces. Now each of these pieces is charged with a magnet so that the pointed end is the south, and the round end is the north pole. Now take these pieces of magnet, and join them...

"Ball Magnet" Roller System I am trying to design a rolling 'ball magnet' system similar to this video as a prototype for a specialized version of it I want to try on a robot this year: I want to gain a solid understanding of all the factors for constructing something like this and the...