What is Electricity and electronics: Definition and 13 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. O

    I Efficiency of computers vs. brains

    Hi, I’m an undergraduate student interested in cognitive processes. I’m about to ask a very interdisciplinary question, and so hopefully I can find a physicists that can take on the challenge. What is the fundamental reason behind why modern electronic computers (transistor computers) are...
  2. P

    Understanding Kirchoff's Law and Solving Circuit Problems

    Homework Statement How do I calculate the current I3? Homework Equations I know that I1 = I2 + I3 and that I2 = 0.4 The Attempt at a Solution So we have a voltage source of 3.7V I would've thought that the equation for a clockwise circuit be 0.4R2 - 3.7 - 200I3 = 0 which gives me an answer...
  3. J

    Which circuit shows the correct connection and values?

    Homework Statement Question: For the circuits shown in Fig. 6, voltage meters and ampere meters are used to measure the voltage across the load and their current flow. If the Red Probe is plugged into the “+” terminal of the voltage meter and ampere meter, which circuit(s) show both the...
  4. J

    Which graphs represent different types of current flow?

    Homework Statement (1) Name the waveform(s) that represent a periodical current flow. (2) Name the waveform(s) that represent a direct current. (3) Name the waveform(s) that represent a non-periodical alternating current. (4) Name the waveform(s) that represent a current with a non-positive...
  5. EEristavi

    Engineering Electronic/Electric circuits and schemes & DIY projects

    Hello, I want something were I can find electric/electronic schemes and circuits to built by myself, starting from basics to complicated ones (with explanation, why and how it works). P.S. I'm also interested in books which involves other fields (eg. chemistry) and DIY projects
  6. Brandon91man

    Electrical DIY Solar Power System: Questions & Answers

    Hello, I've been building my own solar panel system and throughout this process I've accumulated a lot of questions. If anyone could help answer them I would greatly appreciate it! First I'll start off explaining what I have. A polycrystalline solar panel 17V 2.2A and a mono crystalline panel...
  7. D

    A Dipole moment at the sub atomic level

    The following mechanism leads me to wander that a moving neutral object (compose from atoms) in vacuum may generates electric filed due to very small dipole moment. I propose that when atoms force to move in a certain direction the force propagates within the atom. A retardation in movements...
  8. R

    Hard Circuit simplification problem

    Homework Statement Everything is in the picture. Question 3(a) This is for preparation for a contest. http://i.imgur.com/FtiKaYw.jpg Homework Equations V=IR The Attempt at a Solution I calculated the total resistance of the first circuit and used that to evaluate V(AB). But this is in...
  9. marciokoko

    Why does current remain the same in a series circuit?

    Hi Im studying electronics off the web (btw I am looking for a good online course). My background is in Biochemistry and I've gotten into programming (6+ years) and recently Arduino projects (1 year). I am trying to get a better handle on electricity. As I am reading about Ohms law here...
  10. N

    Electrons & Holes: Carbon Nanotube Symmetry Properties

    Well here's the problem carbon nanotubes possesses a electron - hole symmetry .my question is to what property of CNT'S does this symmetricity attribute to ? in otherwords if we dope this with a material with more electrons / holes what property will change ?
  11. Comfort_Cube

    Want to make sure I got the basics of voltage drops

    In my head, I'm using (delta)(gravitational potential energy) as an analogy to the (delta)(electrical potential energy). So, with a DC circuit with loads connected in series, we can observe a voltage drop across each load. Now, because the current remains the same throughout, it must mean that...
  12. RelativeJosef

    Currents through a circuit (junctions/series/parallel)

    Homework Statement Find currents through M and N Homework Equations Current out must be current in. The Attempt at a Solution I think that it is simply 3 parallels running with 5A of current. So, M is in series with the 2A current thus also has 2A of current. Would N also be in series with...
  13. thegreengineer

    Basic Electronics: Transistor confusion

    So, recently I started learning about electronic components and then I started learning about semiconductors. The one which I've been having some real trouble to understand its function is the transistor. So I bought an electronics textbook called El ABC de La Electrónica (The ABC of Electronics...