What is Electrical: Definition and 1000 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.
Summary:: I am a student and i plan to study electrical electronics but i don't know how to go about it.Anyone who is into it can you please guide me on how to become one
I am a student and i plan to study electrical electronics but i don't know how to go about it.Anyone who is into it can you...
I have a heater for my home bought from another country with a different plug, it's ok, it's easy to get an adapter to plug it in, which I often did, however, since it's a heater, I have a question, do I also need to put into consideration of the power ,watt and volt something?? or as long as...
I am currently an ambitious sophomore in high school aspiring to become an engineer. Generally, I love physics, chemistry, biology, and I'm interested in computer science. I am interested in aeronautical, biomedical, chemical, electrical, environmental, computer, mechanical, materials, nuclear...
A rod with a circular center in the middle (which causes the rod to change direction by 90 °) has an evenly distributed linear charge density 𝜆 of electrons along the entire rod. Determine the electrical potential of the red dot in the figure below which is at the center of the circular round...
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Happy New Year!
A typical modern turbofan engine system creates lift as well as propulsion for the aircraft. Somewhere inside the system, the fast rotating device also works as a generator (alternator) to produce the electricity powering electrical/electronics equipments. What is the...
In my search, I have been looking for any data that might explain the RF resistance from 3 to 30 MHz range of the two basic types of copper oxides that form on the outside of bare copper wire. I believe these oxides become semiconductors and have large range of impedances. Due to the nature...
I assume that because there is a resistance, the polarity of the voltage must be the same as the charge flow, and thus the current, in order for energy to flow in the same direction.
For instance, could I use the example of a light bulb (the resistor) plugged into AC lines; we know that if the...
Assume that an infinite metallic plate A lies in the xy-plane, and another infinite metallic plate B is parallel to A and at height z = h.
The potential of plate A is 0, and the potential of plate B is constant and equal to V.
So, there is a uniform electrostatic field E between plates A and B...
I understand that the turbine drives rotational motion of a low and high speed shaft which rotates within the generator, but how exactly, and with what components/materials does this create electrical energy? Is there a minimum required rotational speed or torque required to generate...
A textbook gives an example of an ideal mass striking an ideal string here:
This is drawn as an equivalent electrical circuit as follows, where each R represents one of the two string segments the mass interacts with (ie. the string segment to the left of the mass and the string segment to...
When a voltage is applied to a semiconductor at RT, the thermally excited electrons in the conduction band can move freely, similarly the hole that is generated in the valance band. Suppose we drop a voltage across the semiconductor. The electrons in the conduction band moves towards the...
This is not my subject, but I need to know if I can convert 10 PSI to energy. for example, If I have a permanent magnet motor rotate X time (RPM) to produce 10 PSI. Now Can I invert this process, if I have 10 PSI and let it pass on a permanent magnet motor, How much electricity will produce? in...
In the attached picture, I’ve drawn a crude schematic of the motor circuit. It is fed from a switchgear feeding 3 total motors.
The feed contains 2 parallel conductors on each phase and ground. The equipment ground reads 12a going back to the switchgear, 6a per conductor. From the starter to...
One of the big news stories this week is the pre-emptive blackouts in California. Some commentators have said such events could never happen in their country. Why do we read of USA electric supply problems more often than in some other countries?
Are there significant differences in...
Can tablets like apple ipad be considered an "electrical" equipment? I know it falls under electronics. But could it be electrical since the adapter is plugged to electrical outlets?
I've been given this question for my TMA2, I've tried looking at the learning material but it gives no information on how to calculate the gap? Does anyone have a formula for this? Or can someone point me in the right direction?
Thanks
Hello,
I am Harshil from india. I have completed my Bachelor's in electrical and now i want to do Master's in Astronomy, so i have few questions please answre it...
1) Can i get the admission in MS/Msc astronomy if i have done electrical engineering?
2) If the answer of first question is...
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I want to do what a mechanical engineer does but with the electromagnetic force. What should I study mechanical or electrical engineering? An ideal job for me would be designing the magnetic system for motion in a maglev train, for example.
Hello,
First of all I want to say that I am not an EE, I am an ME but I am working for an EE laboratory on campus and am trying to get a force from and electrical circuit on a project here.
I am using the following equations:
F = 1/2*L'*I^2 (where L' = H/m)
and
F =...
Hello .
Is there any EE who thinks he had to go the extra mile in studying physics to this point in his career ? What courses did you take in both physics and mathematics? Did you read any topic on your own ? I'm really interested in your answers :) .
I think i would like to get into IC design...
As the title suggests, I'm hoping some of you have some favorite resources for a self-studying novice. I'm sure there are a LOT of places online (and in print) to learn, but if anyone can help point me in the right direction I'd be very appreciative. Cheers!
I want to know what is the material that has a moisture and electrical properties response ?
Do I have an idea to create an electrical device that is related to moisture using some materials that are responsive to moisture and electrical properties
Hello everyone,
There is an electrical field inside and outside (at the same time) the spherical hollow conductor when we place positive or negative charge inside, isn't it?
I know this is because of the induced charges on the inner and outer surfaces of the conductor. There is no field inside...
It is a common center-tap transformer which is electrically demonstrated as in figure (ideal one);
In my opinion, open circuit and short circuit tests cannot be applied directly. How can I place secondary reactances ? And how can I test its all parameters in laboratory ?
An electric oven is heated using electricity from a 110 V power line. The power line is connected to a resistance heater in the oven, and the current through the heater is found to be 1.0 A. Assuming the heater is 100% efficient in converting electrical power into thermal power, what is the...
In theory or at least in my head, it seems simple enough to me. A simple water pump, such as a pool pump pushes water through a pipe into a water turbine and recycles the water directly back to the pump. With some of the hydrogenerators I've seen out there, they produce far more power than the...
To write the equation I took as the control volume the following block:
and the equation I wrote are:
$$ 6m_{f} c_{p_{f}} \frac {dT_{f}}{dt} = 6P - \frac 1 {R_1} (T_f - T_g) \text{ for the fuel}$$
$$ m_{g} c_{p_g} \frac {dT_{g}}{dt} = \frac 1 {R_1} (T_f - T_g) - \frac 1 {R_2} (T_g - T_c)...
hello, i have a problem in comsol multiphysics, i want to relate many terminals to each other to buid a current circuit in 2D geometry.
I was thinking to simulate the capacity between winding wire of a coil. So, I have to choose boundary conditions in the winding wire which are Terminals and...
How do I build a device that creates
An electrical discharge between wires? I can build an oscillator. Do I
Connect an oscillator to a transformer and connect the transformer to a pair of wires?
Hi ,
Could somebody explain how to DERIVE the canonical postulate [Xcap,Pcap]=ihbar ? The idea of Pcap operator's origin as -ihbar d/dx also is found puzzling .
Hello everyone,
I am studying at the moment electrical stimulation of nerve fibers. I encountered this image which compares cathodal and anodal stimulation but illustrating the anodal block ocurring with cathode current. But I don't really get the point of the image, could someone clarify it...
Hi, I'm trying to make a realistic scene, in which water is kept under constant electrical charge. If the power is around 75 milliamps, and it's in a stream about twenty feet across by ten feet deep, would this affect water temperature? Thanks!
Mentor Note -- Thread moved from the technical forums, so no Homework Template is shown.
So, we've conducted an experiment on resistors in a circuit. The theoretical calculation was based of on E-24 series color band table and the measured resistance of the resistor was measured by a meter...
Hi,
I have always held (and still do I suppose) the view that gravity is much weaker than the coulomb electrical force due to the fact the equations are so similar you can just compare the constants from each equation showing that the graviational force is many orders of magnitude smaller...
Hi everyone. I was just out in my back garden and was watching the water from someone's shower pour down the pipe and out into a drain. I was thinking if all of the used water from my house just goes down a drain then why not try make use of it.
If the water system continues after use and takes...
Is there any material/s that will handle CVI furnace temperatures (1250 C) and will either repel carbon deposits or react with it to create a compound that is not electric conductive? Trying to contain power to the heating element without shorting it to the base/ground through heating element...
Hey guys!
So basically I'm still finding hard to decide what my specialization field should be next year. I'm really torn between a major in Electronics with a minor in Power Systems with some programming additional courses OR major in Power Systems with minor in Electronics. My favourite...
While working on an old electric iron, I found this joint in the wires:
Any idea what this joint is? Does it have a special name?
The wires are in a horrible condition, so I have to change them. How can I build this joint by myself? Or are such wires readily available in the market?
Homework Statement
y(t) = x(1-5t)
Homework Equations
noneThe Attempt at a Solution
well I've never looked at the stability of a signal which has a time scale and shift. My guess is that it is stable as anything I can provide as input will output a bounded signal.
Ex: if x(t) is u(t)
then...
Good evening, it's been a while since my last thread here in PF. I will go straight to the point:
I want to measure temperature using an NTC3950 thermistor. My circuit diagram is as follows:
It's basically a voltage divider. By varying the temperature acting upon the thermistor the output...
Good evening everyone,
My name is Ricky and am in my first year in becoming an electrical engineer at Olympic College in WA. I am in a technical communications and need to write a discourse community analysis paper. Part this paper is interviewing someone with at least a BS in electrical...
I'm interested in the following general question: Assume x,y,z is an axes system, and that the y-z plane is occupied by a conductive plate at a known potential V with respect to the earth. Now, a conductive material M of neutral global electrical charge is placed at some distance of the plate...
There is some controversy as to why the spectral content of vinyl records contain frequency "information" above what the analog tape recorder was capable of capturing.
A thought experiment:
If I have a piano that has a key which plays 15khz (primary freq. of that key's piano string), what...
Homework Statement
sorry just started my hnc in engineering and electrical the worst part for me
is this right
a current is applied a magnetic field is generated. current is reversed zeros its repeat. metal maintains degree of magnetizem dipole aligment. the magnetic field lags behind the...
Homework Statement
I have a current source of 2mA in parrallel with a resistor of 9.2kOhm and a short. What is the current through the short?
Homework Equations
The Attempt at a Solution
I always thought shorts had an infinite amount of current but maybe I do not quite understand the...