# Tagged Questions

The kind of magic without which all of this wouldn't be possible. This tag should be used for questions about the **physics** of the fields that charged particles create and how these fields interact. It should not be used for all questions involving electromagnetism, that would be everything on ...

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### capacitance sensor between humans

I am using this module: https://www.adafruit.com/product/1374 My idea is to sense a person wearing this module and when touched by another person, the LED lights up. I read numerous articles and ...
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### Do we have a material that reshapes itself depending on applied voltage or electromagnetic field?

I am thinking to control the physical world by applying signals to a magical material. The material must have the ability to change its strength from a very solid state to a dough like state back and ...
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### Could gravity waves generate electricity in metal? [on hold]

If gravity waves passed through a metal sheet or wire could it generate current or voltage because of squeezing and stretching. OR could it generate voltage because of single charge it possess.
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### Body interference in my analog multiplexer, maybe AC electromagnetism induction?

I just wired a CD74HC4067 analog/digital multiplexer to a matrix of leds. The multiplexer is wired to control the LEDs, and is connected to an arduino board, which is connected via USB to my macbook ...
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### Electromagnet Circuit

I'm working on a small project to power a magnetic lock that deactivates when a series of switches are turned on. I've re-designed my circuit based on help from another post, but isn't supplying the ...
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### What happens if a series of EM waves pass through an inductor?

An inductor takes an AC current and produces a magnetic field. An EM wave is made of an electric field, and magnetic field propagating through space, so can a series of EM waves passes through an ...
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### What is the significance of the current rating of a power source?

Assume, I have a copper coil (solenoid) with exactly 1000 turns. When I connect a multimeter across the 2 ends of the coil, the multimeter gives a resistance value of 20 ohms. Now I have 2 power ...
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### What are the advantages of controlling an ac pm motor in abc or qd0 reference frame?

let's refer to the following (vector) control schemes: Qd0 is the synchronous reference frame, with d alligned to the pm magnetic field. the system is balanced and symmetric (so no 0 component). ...
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### What type of components necessarily pickup EM waves in antennas? [closed]

I understand the transmitter part of telecommunications, but what type of electrical components are used in antennas? I understand that the transmits a signal which the antenna recieves via an EM ...
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### Query regarding Electric Potential and Electric field intensity

We have a relation between Electric field(E) and potential(V) as E = -∇V and V = -Integral (E)dl In such case, V have to be equal to -E.D ::: V = -E.D but in ...
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### zvs inductive heater and electromagnetic spinner at same time

I'm trying to make a inductive heater magnetic spinner vacuum oven, and wondering if the same coils might be wound for both. Inductive allows faster heating and direct heating through the glass vs ...
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### Is reed switch sensitive to DC magnetic field?

How would I know if a reed switch in parallel to a DC wire in which is flowing current can be closed by the magnetic field produced? If yes, what's the minimum current required?
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### How to make a simple manual gengerator that can produce a 9 volts of electricity?

I have a project from my subject which that project was to create a manual generator that can produce up to 9 volts of electricity. I've been searching some samples that is homemade manual generators, ...
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### High voltage step up power module

I have bought the stuff in the image below from eBay in order to generate an electrostatic field. But the spec of the item is, well ..., written in chineese with some english flavor. I have tried ...
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### Can Copper Magnet Wire have layers in a coil?

I know Magnet Wire has a thin layer of insulation but when i make a coil, can I stack/layer the wire on top of each other or will it just perform the same with normal wire.
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### Cause of skin effect: eddy current inside conductor

We all know very well that due to eddy current (back EMF) generation within an AC carrying conductor, "skin effect" occurs. Eddy current density: Highest at center of conductor core Lowest at ...
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### How does inductance change with presence of different directional magnetic fields?

If I design a coil driver for a certain application, I assume there is a fixed load right? It may have drive any inductance between an interval but you can not drive any coil, because the driver is ...
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### electromagnet repelling permanent magnet [closed]

I have an electromagnet (turned off) with an iron core in front of a permanent magnet. At this stage they attract each other. Will any current do if I want them to repel each other, or is there a ...
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### How to run ammeter in low resistance?

I need to measure current in a small electromagnet powered off 3 x AAA batteries in series. This is the manual for my multimeter. When I run this multimeter in series and try to find the current, the ...
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### How to find the polarization (phase) of the virtual source if image theory is used

Consider a radiating element (actual source) is placed above a ground plane, and if we apply image theory to determine the E-filed, the virtual source will be placed below the ground plane and ground ...
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### is there any impact of Electron's spin in CRT?

fact-1. Electron's (or any-other particles) magnetic behavior depends upon mass, charge and spin. fact-2. All electrons are not the same. Though all electron have the same mass and charge; an ...
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### Controlling the frequency of AC used to energize an electromagnet

I am trying to build an electromagnetic pendulum which essentially has a pendulum arm with a permanent magnet at its end which is 'kicked' by an electromagnet placed at the mean position to drive the ...
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### In electromagnetic inductance, which one is more efficient, to focus all power to move one part or split it to move both at the same time?

Assuming equal force is used, which one would be more efficient when it comes to generating current through electromagnetic induction: to use 100% of available force to move the permanent magnet only ...
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### can something have electricity flowing in it without being connected to electricity? [closed]

Can something have a powerful electronic flow throw it that's remain constant for a very long period of time if it was somehow electronically charged before hand?
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### Electrical Load increase on Generator = More Fuel Consumption

Why does more electrical current drawn from generator leads to more fuel consumption? I understand that it's due to conservation of energy, I just want to know what the phenomenon or reaction is ...
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### Building a magnetizer

I'm building a simple magnetizer for the realization of a physics experiment, bought yesterday components for the construction of the same, I am following the scheme of this site: The final ...
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### Magnets in Transformers Design

What is the advantages, and disadvantages of using neodymium magnets instead of ferrite cores in transformers? How would the magnetic flux density vary of such a transformer utilizing a neodymium ...
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### How to calculate energy transfer in inductive heating?

I designed an inductance heater. Its inductor is calculated 50 uH as below: And I draw 9.4 A AC current at 33 Khz of it. But, I want to know how to calculate the transferred energy to the ...
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### Coil Gun Schematic [closed]

I have a question. I have been looking at making a Coil gun lately and i had an idea for a simple one. Just need to know if it would work. Basically: Battery-->Switch-->Diode-->Transformer-->Coil For ...
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### Electric motors with both stater and rotor as electromagnets [closed]

I am totally new to the Electrical area. I wanted to do a project on Electric car which needs an Electric motor which is highly powerful and efficient. Are there any motors which have both stater and ...
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### By measuring the electricity generated, is it possible to calculate how fast the turbine was moving?

Say a wind turbine is moving at varying speeds. From the electricity it generates, would it be possible to calculate/replicate the motions of the turbine? How accurate can these measurements be? Will ...
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### Ripple flowing through probes connected to the same point!

While trying to filter the ripple of my switching PSU, I've come to a phenomenon that is probably well known to professionals, but seems absurd to me. Admittedly, my scope is not of the highest ...
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### Perpetual motion desk toys and magnets [duplicate]

As far as I know, perpetual motion orbital desktops like below use an electromagnet in the base. Why aren't permanent magnets used on both ends instead? Does anyone know where I could find a ...
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### Why compass module is affected by its x,y position, if my phone's compass work in the same environment?

I am using hmc5883L on an autonomus robot. It shall remain in a 1 meter squared area. I have recently discovered that its reading changes up to 20 degrees on different positions even when it is facing ...
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### Range of Electromagnetic Waves/Radio waves? [closed]

What basically determines that how far the electromagnetic waves will travel away from the source ? In our world where there is air and other materials how electromagnetic waves would generally ...
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### Magnet Wire AWG?

I need some magnet wire for a school project, it will be wrapped around a ~5cm nail and powered by either a 9v or a couple AA batteries. It won't be doing any heavy lifting or anything, just some ...
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### Electromagnetic Radiation and Communication! [closed]

I read that the accelerated charges create electromagnetic field/spectrum which consists of following different waves: gamma X-rays ultraviolet visible light infrared microwaves radio waves gamma,...
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we are trying to built Electronic Locker Which is Controlling by a specific Combinational Password but we have a Problem with (4x4 Switch Matrix Numbering Order) In the Circuit Diagram the numbering ...
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### Low weight split core transformer on 11kVA transmission line

I've seen transmission line energy harvester's that utilise a split core transformer. Here is an example. However, I fail to see how this is possible when a transformer cores which are small enough ...
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### converting inductance to electromagnetic force

How might one determine the amount of electromagnetic force produced by an unshielded inductor? E.g. How much holding force does a 600uH unshielded inductor posses? Or alternatively in reverse: How ...
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### Electromechancial locks used in a turnstile

I was looking to build a RFID operated turnstile similar to picture below. I will have RFID readers on both ends where the door would open from either end only if the RFID is authenticated on either ...
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### accuracy of magnetic field sensors in electrical vehicles

For coordinate system alignment purposes, as demonstrated in the figure, I want to use the smartphone's virtual orientation sensor. However, the virtual sensor is using a combination of acceleration, ...
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### Designing a generator

I am modeling the output voltage of an AC generator and I am using/I chose the following specifics: Number coil turns = 300. This is 1.02 mm gauge copper wire, so knowing the density of copper, I ...