What is Electricity: Definition and 999 Discussions

Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others.
The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field.
When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of positive charge from an arbitrarily chosen reference point to that point without any acceleration and is typically measured in volts.
Electricity is at the heart of many modern technologies, being used for:

Electric power where electric current is used to energise equipment;
Electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies.Electrical phenomena have been studied since antiquity, though progress in theoretical understanding remained slow until the seventeenth and eighteenth centuries. The theory of electromagnetism was developed in the 19th century, and by the end of that century electricity was being put to industrial and residential use by electrical engineers. The rapid expansion in electrical technology at this time transformed industry and society, becoming a driving force for the Second Industrial Revolution. Electricity's extraordinary versatility means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is now the backbone of modern industrial society.

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  1. B

    How far would physics have progressed without electricity

    How far could the study of physics have advanced without the discovery/invention of electricity and electrical power? Or in other words, what fields and major breakthroughs could not have been achieved without the availability or knowledge of manipulation of electricity?
  2. A

    Trapping light without electricity

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  3. J

    Electricity in a Vacuum: Investigating 1e9 Voltage

    Good day. What happens if a vacuum to put two electrodes, 1 cm apart, and electrical voltage in 1e9? Thank you.
  4. Steven Ellet

    Can Static Electricity be Measured and How Dangerous Can it Be?

    How do I measure static electricity or is it even possible?
  5. F

    Equal and opposite forces with electricity

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  6. E

    Difficult Introductory Electricity Circuit Problem - Capacitors

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  7. F

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  8. T

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  9. Manraj singh

    Can a Rotating Fan Be Used to Power a House?

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  10. R

    Can a Charged Particle Move in a Straight Line in a Nonzero Magnetic Field?

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  11. S

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  12. O

    Current from static electricity

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  13. Gamma

    Electricity Safety: AC & DC Current Limits for Intro Physics Labs

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  14. T

    Static Electricity vs Current in a Closed Circuit

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  15. C

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  16. P

    Electricity and Air: A Fascinating Interaction

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  17. Astronomy

    Electricity Formula: Difference between E=σ/2ε0 and E=σ/ε0

    Hi I want to know what is the diffrences between E=σ/2ε0 & E=σ/ε0 of course I know we use the first for a very huge page but what about the second formula? I saw in some solving of question when we have 2 pages infront of each others we use both of them... I want to understand the deep...
  18. C

    Design lift without electricity

    This is my project..you have any idea how can generate power to lift elevator.
  19. B

    How is magnetism generated around an electron?

    how can magnetism be derived from electricity at the sub atomic level?? how is the magnetic field generated around an electron? if magnetism is just generated due to angular momentum of the electron it is said that if calculated the spin of electron would exceed light speed ; so will it work...
  20. P

    Static Electricity: Charging by Friction: Understanding MIT demo

    MIT has a Physics Demo called "Rubber and Glass Rods with Tinsel and Balloon" (Not sure if I can post links but easily found on youtube). I have watched the video several times but am a bit puzzled. First the lab technician charges the rod by friction but then when he moves it close to the...
  21. M

    Understanding Voltmeter Sensitivity and Load Effects in Electrical Circuits

    Hi. I have a problem understanding a question for my electronic engineering course. We have a subject that's directly translated to 'the knowledge of electricity and measurement techniques'. I do hope this is the correct forum to ask for help at. Homework Statement Given the...
  22. J

    Measuring electricity passed to ground from an antenna

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  23. N

    Static Electricity and Number of Electrons

    Homework Statement When you rub a gold sphere with rabbit's fur, the gold takes on a negative charge (and the rabbit fur positive). Suppose the gold sphere has a mass of 190.0 g and it obtains a net charge of 0.540 μC. Calculate the ratio of the number of electrons added to the gold sphere to...
  24. E

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  25. B

    How to safely create static electricity from AC current

    Is there a simple way to "make" static electricity from an AC outlet? Looking for a way to make my hair stand (what is left of it) on its end for an experiment. Thanks for your comments in advance.
  26. W

    Introduction to Electricity: Basic AC/DC, Resistors, Capacitors, and More

    Hello, I am looking for a basic introductory textbook on electronics. Since it's introductory, nothing too rigorous required. Topics: Basic AC/DC introduction Current, Charge, Voltage Resistors Series/Parallel circuits Ohm's Law Capacitors Semiconductor devices (diodes, doping...
  27. B

    How can you use electricity to create static charge and bend water?

    Hello all, I watched a youtube video where you can rub a plastic tube on your hair, and the static electricity generated will pull a stream of water falling from a faucet. My question is, how would this be possible to do electrically? Meaning, using electricity or a battery powered...
  28. M

    Static electricity and circuit breakers

    Hi I have seen electric technicians while racking out high tension circuit breakers, use a wire that has one end grounded and they use the other end to touch the bus bars on the breaker in case of a static charger, they carry out this procedure before they do any work on the CB in case they...
  29. D

    A simple question about the flow of the electricity

    Hey guys! I'm trying to get a bettter undesrstanding of how the electric circuits work. But I do have a rather simple question. So, in the internal circuit we give energy to the charge. Let's say that I have an electricity source and two resitors, like this: So when passing through circuit...
  30. hideelo

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    I know that magnetism can be explained as the relativistic interaction between say a current, and a moving charge. My question however is twofold, is magnetism nothing but electric forces when relativity is taken into account? If the answer is yes, does that make magnetism a sort of psuedo-force?
  31. bcrowell

    Free edition of Purcell, Electricity and Magnetism

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  32. K

    How Is Electricity and Magnetism Used In Computer Science?

    I am a computer science major and we are required to take two semesters of physics. First semester is based on mechanics and the second semester is focused on electricity and magnetism. I was wondering how these topics are used in computer science and in what specific area? I have tried looking...
  33. S

    Electricity from a kerosene/gas mantle?

    Like the title says I was wondering if it would be possible to generate a couple of watts of electricity from a kerosene or gas mantle. Less than 0.5% of the energy in the fuel is being converted to light which means that in the 33kJ per mL of kerosene nearly 9 watts is being lost as heat...
  34. M

    Aircraft Certification (Static Electricity Dischargers)

    The little wicks placed at the wingtips to get rid of static electricity on the wings and body of the aircraft are vital to aircraft. I am interested in what the certification requirements for placing these ont he wings. I assue the formula of would include things like 1-surface area 2-speed...
  35. B

    Wireless Electricity: Magnetic Resonance vs. Magnetic Induction

    What is the difference between magnetic resonance and magnetic induction when it comes to charging devices and other types of wireless electricity. I was doing some research on this but was not able to find a clear answer. If someone could help me with this that would be greatly appreciated...
  36. F

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    Homework Statement Using physics knowlege, why do some electricity pylons collapse in extreme temperatures. Homework Equations The Attempt at a Solution Don't know the physics formulas or equations that could be used. High winds would force the pylons to collapse as the structure hasn't been...
  37. G

    Static electricity - Quantity of charge induced.

    Hi all, Let us say I have rubbed cat fur with nylon. Is there any relation for determining the amount of charge (in Coulombs) induced on either of the materials? Thanks in advance.
  38. D

    Does Work Done by a Spherical Force Field Depend on Path?

    Homework Statement A force eld E has the spherical components Er = (2Dcosθ)/r3 Eθ = (Dsinθ)/r3 E\phi = 0: (a) Evaluate by line integration the work it does in taking a point (parti- cle) from point A in the diagram to point B via the quarter circle r = a; 0 <...
  39. D

    Converting everyday heat energy into electricity

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  40. K

    Exploring the Current Frontiers of Electricity & Magnetism

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  41. M

    Electricity circuit question, amplitude resistor?

    Homework Statement The ac circuit has 3 components in series: a Capacitor C=120μF, an Inductor L=100mH, and a resistor R=7Ω. A) Find the amplitude of the voltage across the resistor R in the LCR circuit below, when operated at a frequency of 45 Hz? B) What is the phase difference...
  42. T

    Relationship electricity and magnetism

    Hello, I have started reading a beginners book (from the "stop faking it" series) on electricity and magnetism. Its supplied with funny little experiments to help me understand the topic. But I have trouble understanding the intimate relationship between electricity and magnetism. I believe I...
  43. L

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    So, I don't want to disclose why I want to know about this because its to do with a friends invention and it would be unfair to publish too much information without his consent. That's my disclosure so to speak. I'm interested in how static electricity is managed in vehicles. I remember...
  44. T

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    Greetings PFers I’m thinking about building a Tiny House similar to the one below, except outfitted with solar power. http://www.tumbleweedhouses.com/products/weebee/#ad-image-0 A Tiny house is a small (~120 sqft) home on a trailer bed. I’m interested in designing one that is equipped with a...
  45. J

    Electricity - AC generation, supply and return question

    I am sure this is a set of naieve question first of all. However i'd appreciate someone taking the time to enlighten me, as my mind is boggled by this and has been for some days now. I have watched numerous videos on the subject of electricity but am still somewhat confused. My issue is taking...
  46. Newtons Apple

    Exploring the Significance of Coils in Electricity and Magnetism

    hey everyone, I have a questions, that is very general, and perhaps, silly... but why are coils so significant in terms of electricity and magnetic fields? why is it when you push a magnet through a coil, you get a charge, but not when you touch it to a straight copper pipe? Or when you see...
  47. P

    What Are the Viable Alternatives to Electricity for Future Energy Needs?

    As technology has advanced, we have come up with ways to produce and use more energy, and have come up with many different ways of doing so. Most of what I know of using energy for households or factories or big machines is that they use electricity, as a way to convert fuel, heat, wind...
  48. L

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  49. A

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  50. gauss44

    Do super concentrated solutions NOT conduct electricity well?

    I know that pure water doesn't conduct electricity well, and that adding an electrolyte generally increases conductivity. However, does there come a point where increasing the concentration of electrolytes actually DECREASES conductivity?
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