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Questions tagged [electromagnetism]

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Electrical Two body problem

Depicted above is the instance of a spherical shell, at which a point on that shell is negatively charge. This shell is fixed at an arbitrary point in space. Inside of that shell is positively charged ...
Jais's user avatar
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3 votes
1 answer
205 views

What are the benefits of using a spring as a drive screw in this electronic deadbolt?

The Schlage FBE365 electronic deadbolt uses a DC motor attached to a helical screw to raise and lower the C-shaped piece shown. The way the rest of the mechanism works is not important for this ...
Ryan's user avatar
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-1 votes
1 answer
33 views

If drilling to the mantle is too hot for drills and too hard for millimeter waves, why not use positrons?

Would it be possible to make a millimeter sized hole which extends down to the mantle, and fill it in with a heat sink, to draw the heat upwards to a mine for steam production and then power?
Jais's user avatar
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0 votes
0 answers
23 views

New Method for a Passive Magnetic Bearing

Is it possible to create a passive magnetic bearing by layering the outside of a shaft with a magnetic film and placing a magnetic ring on the outside. The outer layer of the film would have a north ...
ARJ's user avatar
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0 votes
1 answer
217 views

Mesh Size and Thickness for Faraday Cage?

I've been considering a double faraday cage of 1/4in 23-gauge wire and 1/8in 27-gauge wire. With this setup would the 1/4in on the outer shell and 1/8in on the inner or the 1/8in on the outer shell ...
CoryG's user avatar
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0 answers
39 views

What materials are most transparent to magnetic fields?

What common materials are most transparent to magnetic fields? I have two applications; in each case I want minimal distortion and degradation of the magnetic field: Wrapping/surrounding a magnet (...
RoUS's user avatar
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0 answers
25 views

When a permanent magnet is quantum locked above a superconductor and is spinning what variables/calculations dictate how fast it spins?

Basically, I want to know whether it’s the size of the permanent magnet, a.k.a. the strength of the permanent magnets, magnetic field, or the super conductor that decides how fast it will spin whether ...
Ink's user avatar
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0 votes
1 answer
43 views

How do I design this magnetic bed?

I am looking to design a bed of magnets that I can lay on for health improvement. Ignoring any health concerns, the objective is to create the "purest" AND strongest negative field (NORTH ...
Gabe's user avatar
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1 vote
0 answers
39 views

Trying to understand Nathan Stubblefields 1898 American Patent #600,457

I find this solenoid to be intensely interesting. It has a number of unique properties: The coil wire is made from dissimilar metals so that the voltage is internally produced in the coil. The ...
Instrumentation-Tech's user avatar
1 vote
2 answers
61 views

High voltage wires

We have bought a house near high tension wires (at a distance of around 20m). Will it be noisy during the rains, and more importantly will the ionization increase the risk of cancer?
Shrey Iyer's user avatar
0 votes
1 answer
96 views

Homopolar motors - a curious realisation

So I've been chasing down devices with unique operational characteristics looking for potential in energy generation and I ran into these things: homopolar motors. About 9/10 of these things are a ...
Instrumentation-Tech's user avatar
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0 answers
18 views

Inductor calculations helper script and motor idea

I have an idea for a motor involving the use of a flyback transformer to recycle EMF in a custom designed pole-to-pole repulsion-attraction DC motor. I wrote a script to help with setting design ...
Instrumentation-Tech's user avatar
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0 answers
13 views

How could we aproach development of touchscreen with morphing surface or morphing keyboard?

There is this technology of braille e-readers. It is relatively simple and reliable but it never had much commercial success probably because small customer base. In past a company called Tactus tried ...
Martin Pavlíček's user avatar
0 votes
4 answers
56 views

Why does restoring force of a spring vary directly with elongation or compression?

The restoring force is electromagnetic in origin, having to do with atomic/molecular interactions. Both electrostatic as well as magnetic forces vary inversly with the square of distance. $F_{_{EM}}\...
Nietsniewton's user avatar
0 votes
1 answer
117 views

Would a conical-shaped solenoid be propelled by its interaction with the Earth's magnetic field?

I am wondering if the interaction between the magnetic field created by a conical-shaped solenoid and the Earth's magnetic field will result in this conical-shaped solenoid being propelled through the ...
user57467's user avatar
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1 vote
2 answers
53 views

Controlled oscillation of a piano string by electromagnetic, mechanical, or other means

What would be a good way to actively control the loudness of an acoustic piano note over time after the note has already been struck by the hammer, such as by actively changing the amplitude of a ...
Dynamic Light's user avatar
0 votes
0 answers
68 views

Any information on magnetic braking with copper?

I have an engineering project where I have to design and build a model of a drop tower from a theme park. The tower itself can be no taller than 40cm. I plan to use magnetic braking with copper to ...
18jbrana's user avatar
1 vote
2 answers
757 views

Braking system for a miniature ‘Drop tower’ rollercoaster

The tower itself is only max 400mm. Designing the lifting system isn’t the problem but slowing down the gondola is posing a slight problem, any suggestions? I have looked into using magnets but I can’...
Ruperttt's user avatar
0 votes
0 answers
35 views

Accelerate an object in a current-carrying coil

I'm currently trying to come up with some concept ideas for a physics game / riddle. The player has to get an object from one side of a horizontal, current-carrying coil to the other end of the coil ...
Phazis's user avatar
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0 votes
1 answer
113 views

What would be the best capacitor to use for a railgun that uses a capacitor as the projectile?

I have had a long-time interest and fascination with railgun technology and for a long time I have wanted to build a small-scale, simple railgun as a scientific experiment. This railgun is designed to ...
user57467's user avatar
  • 303
0 votes
1 answer
54 views

Viability of bladeless wind power generation

I have recently thought of two designs for bladeless wind power generation; And They both essentially ionizes the incoming wind which then passes through a coil, the flow of charged wind particles ...
Rayyan Javed's user avatar
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0 answers
19 views

How does resistivity affect the susceptibility of a steel alloy to induction heating?

For context, my question is related to the use of heating to elongate studs for casing tightening and loosening. In turbine casing assembly, in addition to torquing the nuts, studs have holes drilled ...
George's user avatar
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0 votes
0 answers
14 views

Why are the indices of term of the Cauchy Stress Tensor and Maxwell Stress Tensor opposite to each other?

For CST (https://en.wikipedia.org/wiki/Cauchy_stress_tensor), the first index represents the plane and the second index represents the direction: For MST (https://en.wikipedia.org/wiki/...
SNIreaPER's user avatar
0 votes
0 answers
36 views

How to manufacture Inrunner BLDC motor core

I need to make a 10 slot BLDC inrunner motor core that is 40mm wide has 10mm inner diameter and 10mm thick. How would I make this? I would want to make it out of mild steel but I do not have a CNC ...
Yassin's user avatar
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0 votes
0 answers
26 views

S-Parameters and Received Power for Implant Antenna

I am simulating an implant antenna using the Ansys HFSS EM simulation tool - the simulation setup looks something like this, with a transmitting (TX) antenna of transmit power $P_{TX}$ and transmit ...
PikaPika's user avatar
0 votes
0 answers
27 views

Design of a 3 Phase Linear Induction Motor

I am a Mechanical Engineer but need to use a 3 Phase Linear Induction Motor (LIM) for a MagLev project. To demonstrate the working of LIM I need to design LIM for accelerating a 10 kg payload to ...
Rehan Jamshed's user avatar
0 votes
0 answers
26 views

How can I transmit the force induced by magnetic torque?

So I'm working on a project where I'm trying to transmit the force induced by magnetic torque onto people's hands, thereby making it a haptic feedback system. This is the stucture that I designed to ...
NakedRaccoon's user avatar
0 votes
1 answer
77 views

How is this Solenoid made?

I ran into this old YouTube video. As you can see apparently it's a solenoid, but the person doesn't explain how it's made. I've never seen a solenoid with such a long stroke, if you can please ...
Ali Moradi's user avatar
0 votes
2 answers
151 views

How does the magnetic field in a synchronous machine with two pole-pairs distribute if I only apply DC-voltage on two phases? (Star connection)

I am struggeling to understand the following: If I consider a synchronous motor with only one polepair and apply dc-voltage to two of the three phases this results in a static magnetic field. The ...
cor3kl's user avatar
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1 vote
3 answers
105 views

How can I keep a low voltage electromagnet on continuously for long durations of time?

Background I have an application that requires an electromagnet (either 5v or 12v) to be powered on for long durations of time (up to a few hours). While looking for one online, I was having a hard ...
Jack Campbell's user avatar
0 votes
0 answers
30 views

Mathematical Modelling of Wireless Power Transfer

I am trying to understand the interaction between a transmitting antenna with a certain transmitting power (denoted PTX in the diagram) and how the radiation pattern of the TX antenna is affected by a ...
PikaPika's user avatar
1 vote
1 answer
81 views

Physics behind a realistic and theoretical DC motor

I am learning about theoretical DC motors where the rotational motion is produced due to torque on either side of a coil. However, after researching real DC motors it seems to me that the winding ...
Cirrus's user avatar
  • 13
-1 votes
1 answer
51 views

I have 2 questions i am not able to solve in applied electromagnetics

I will attach the photos of the questions, it was my quarterly test paper Consider a continuous line charge distribution along the circumference of a circle of radius 1 unit in the xy plane. With the ...
Sai Ganesh K's user avatar
0 votes
1 answer
194 views

How should one wind the coils for a BLDC motor to maximize torque, if nothing else matters?

I'm trying to build a brushless DC motor with six winding arms, pretty typical design. If I'm trying to maximize the torque output of my motor, what would improve the motor best: Extending the length ...
Hinson Chan's user avatar
2 votes
3 answers
62 views

Recent breakthrough on Inertial Confinement Nuclear Fusion at NIF

For the very first time, it has been demonstrated that it is now possible to make Nuclear Fusion generate more energy than is required for its equipment to operate, but it is not entirely clear as to ...
Prakash_S's user avatar
2 votes
1 answer
98 views

How to make the magnetic field intensity from a DC electromagnet bigger without changing its current, number of turns, or geometry?

I'm currently doing a project on magnetic haptic feedback using DC electromagnet. The principle of my haptic feedback system is very simple (figure shown below): A permanent magnet is stuck to the ...
NakedRaccoon's user avatar
0 votes
1 answer
78 views

How to concentrate magnetic fields using the least amount of material possible for a fixed area

So the goal is to a build a device that will redirect field lines from earths magnetic field at the magnetic north pole into a point. The goal is to maximize the area / amount of magnetic flux ...
Sidharth Ghoshal's user avatar
0 votes
1 answer
54 views

Any scientific research papers on electromagnetic active valves using variable viscosity electromagnetic fluids?

I know the title is quite a mouthful, but let me explain (also, I couldn't find anything on the subject, maybe because I'm using the wrong words). I saw some time ago a video about a variable ...
Fulano's user avatar
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1 vote
1 answer
113 views

What are possible applications for room temperature superconductor requiring extreme presssure?

At standard room pressure, the highest temperature superconductor is "the cuprate of mercury, barium, and calcium, at around 133 K" (-140 °C). If pressure can be increased, however, the ...
James's user avatar
  • 113
1 vote
2 answers
45 views

How to calculate voltage change across electrodes in tank of water?

Reposting from https://physics.stackexchange.com/questions/736554/how-to-calculate-voltage-change-across-electrodes-in-tank-of-water because apparently this is an engineering question and not an ...
Matt Helton's user avatar
0 votes
0 answers
34 views

Which is the better magnetic arrangement for a voice coil to give a larger amplitude of movement all else being equal?

Given everything else equal (e.g. same overall amount of magnetic material, same strength magnetic material, same coil, same power supplied, etc. etc.) which of these two magnetic configurations of a ...
Oliver Walters's user avatar
0 votes
0 answers
16 views

Is Poynting flux the same as the Poynting vector?

I need to solve a homework question that asks me to find the Poynting flux. However, I can't find any formulas for Poynting flux anywhere. Is the Poynting flux the same as the Poynting vector?
elvishpotato's user avatar
0 votes
0 answers
23 views

Does improper loading of a dynamic microphone cause damping or affect the coil movement?

Slightly struggling to find the right technical language to frame my question, but let me try... A dynamic microphone is effectively an electrical generator, similar to an alternator. I've read that ...
Vishal Bhardwaj's user avatar
0 votes
0 answers
34 views

How do I draw a circuit for a conducting loop inside a solenoid?

To solve a homework problem, I need to redraw the following diagram in circuit form. The large blue circle represents the solenoid. Inside the solenoid, the two gray semicircles represent a wire loop,...
elvishpotato's user avatar
1 vote
0 answers
27 views

Could electromagnets ever compete with the power of an antimatter annihilation engine? [closed]

So to make this easier to read, I've been using a few terms I'll explain really quick "MPP": (maximum physical potential) "MASS": (maximum atomic structure strength) According to ...
Brownpill's user avatar
0 votes
1 answer
60 views

Why do inorganic LEDs wear out?

Why do inorganic LED bulbs have a limited lifespan? For example, a manufacturer may quote that a bulb or monitor powered by an organic light emitting diode(s) has a lifespan of 50,000 hours, while it ...
CoastCity Lapse 00crashtest's user avatar
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0 answers
52 views

DC Motor Powered Car

So I run an engineering class even though I mostly just do theory myself, so when it comes to actually building stuff I miss some basic ideas I should know. I am having them make a DC motor out of a ...
Patrick Flint's user avatar
0 votes
0 answers
34 views

What is the smallest possible focusable, scaleably intense laser design?

Would anyone here have any ideas towards what the smallest possible laser mechanism across all physical potential might be? I was wondering this for a theoretical machine capable of manipulating ...
Brownpill's user avatar
1 vote
0 answers
41 views

Electromagnetism - DC Motor Design Question - EMF/BACK EMF

I'm not gonna lie - I don't have enough knowledge about EMF and Back EMF so I need you guys , my friend will soon build a DC motor for me but I currently have no idea what design will produce high ...
lidorov19's user avatar
2 votes
2 answers
682 views

Do infrared heaters have a special blackbody radiation specturm?

There are many infrared heaters on the market, that I would put in 3 categories, filament in quartz tube, filament in ceramic, and carbon film (for flat panel heaters). They all claim to be "...
Manu de Hanoi's user avatar