Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [electromagnetic]

Electromagnetism, or the electromagnetic force is one of the four fundamental interactions in nature. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors.

Electromagnetism, or the electromagnetic force is one of the four fundamental interactions in nature. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors.

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Can I turn Radio waves into light?

Wikipedia says that the frequency of light is 300 THz. I've made a radio waves transmitter that transmits about 100 MHz. If I increase the frequency of the transmitter to 300 THz, will the antenna produce spark or light ? Can I do this circuit…
Michael George
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How does an inductor store energy?

I know that the capacitors store energy by accumulating charges at their plates, similarly people say that an inductor stores energy in its magnetic field. I cannot understand this statement. I can't figure out how an inductor stores energy in its…
Andrew Flemming
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Is it possible to generate light with an antenna?

An antenna (e.g. a dipole) is able to radiate at a certain frequency thanks to the EM field generated by a current provided by a signal generator at such a frequency. So, for instance: Voltage source at frequency f (representing an amplifier) +…
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In which direction do electric signals flow?

We know that electrons move from the negative to positive terminal, and that holes flow in the conventional direction of current - from the positive to negative terminal. I've always assumed that this means that electric signals travel in the…
slebetman
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Why can't you put a plane under a trace antenna?

I'm working with RFID for the first time. All the app notes I've read show a separate region of PCB allocated for the trace antenna, with no planes above/below. I want to understand why this is, and if it's strictly necessary. I understand that the…
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Why does magnet wire need to be insulated?

What is it about having multiple coils that enables the magnetic field? Why can't I just have one big wire or threaded wire on a motor? Sorry, it's kind of a baby question but I couldn't find the answer.
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Does Shielding "Electrically" shield "Magnetically" too?

I know it sounds like a newbie question but I can't wrap my mind around it. An electromagnetic field is electric + magnetic field. So this means that when shielding an equipment offensively, for example from avoiding causing interference with other…
user138887
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Why is it so expensive to produce cameras for non visible light?

Typical consumer cameras can capture wavelength of 390-700 nm 400-1050 nm. But why is it so difficult and expensive to produce cameras for infrared, ultraviolet, hard x-rays, etc.? The only thing which differs them are the wavelength and the energy…
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Do square wave exist?

If we send a square waveform through an antenna, will we get square electromagnetic waves with electric and magnetic fields looking like squares? Also, since there is an abrupt/almost jump in amplitude, will we get very high frequency sine waves…
Vishwa Mithra Tatta
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What are some quick, cheap hacks for determining the source of EMI in my house?

TL;DR - Without dumping a bunch of money, is there a quick MacGuyver-y way to help diagnose what's causing the EMI in my house? Longer - I have the curse that I'm a little too technical to be helped here by dummies.com, but not sophisticated enough…
jdowdell
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What makes E-bomb or Electromagnetic pulse (EMP) destructive?

wikipedia says that Electromagnetic pulse As with any electromagnetic signal, EMP energy may be transferred in any of four forms: Electric field Magnetic field Electromagnetic radiation Electrical…
Michael George
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Why no macroscopic electrostatic electromechanical parts?

So, I understand that relays, motors, and other electromechanical devices are almost always electromagnetic devices. Why is this? I know that electrostatic motors exist, but what makes them substantially worse than electromagnetic motors? Note that…
Hearth
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How do I build an electromagnet?

I want to make an electromagnet that can lift a paper clip off of the ground from a short distance (probably 7 to 8 inches). I naively thought of making an electromagnet as a simple task (because of the short videos which make it seem so simple),…
Will
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Why is a clamp meter unaffected by nearby wires?

I understand a clamp meter works by measuring the magnetic field generated by current flowing through a wire. It's well known that clamping 2 wires carrying the same current in opposite directions will show a null reading because one magnetic field…
Zmaster
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How does a electropermanent magnet work?

I’m trying to wrap my head around electropermanent magnetism. I read this wonderful PhD Thesis by Ara Knaian as well as details the history of this concept as well as Kyle Gilpin, Ara Knaian, and Daniela Rus’ implementation with the Robot Pebbles…
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