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.
Hi,
I don't know if I have calculated the electric field correctly in task a, because I get different values for the Poisson equation from task b
The flow of the electric field only passes through the lateral surface, so ##A=2\pi \varrho L## I calculated the enclosed charge as follows...
Suppose two orthogonal neighbouring orbitals ##|\phi _1 \rangle## and ##|\phi _2 \rangle## so that ##\langle \phi_1|\phi _2 \rangle =0##. Applying an electric field adds a new term ##u (c_1^{\dagger}c_1-c_2^{\dagger}c_2)## to the Hamiltonian which u is a constant potential. Obviously, we still...
Hi,
I am reading Griffiths Introduction to electrodynamics. Currently I am solving problem 2.11 which asks to find an electric field inside and outside a spherical shell of radius R.
Inside:
$$\int{E \cdot da} = \frac{Q}{e_0} = |E|4\pi r^2 = \frac{Q}{e_0} = 0$$ The result is $$0$$ because we...
this is the field I was provided
and this is the charge density that I have reached
I tried to use this yet the output was different
I also used Cartesian it gave me the same output as the spherical ones
Here's what I've tried. First of all, I assume that q is positive. For particle A, then, I can write $$q E -k {\left( x _{A }-x _{B }\right) }=m \ddot{x }_{A }, $$ where ##x _{A } ## and ##x _{B } ## are the coordinates of the particles relative to their equilibrium positions from the point of...
Homework Statement: circuits - terms
Relevant Equations: -
How exactly can the electric potential be constant between two points in a wire; (assuming that it is electron current); if the electron is moving from a region of high electric potential to a low electric potential because of the...
I did a thought experiment and I can't figure out what the mistake is.
There is a system of 2 electric motors weighing 1 kg each with batteries in the Earth's orbit.
The motors are rigidly connected by a 1-meter-long bar.
If one motor starts rotating in one direction on a signal, the entire...
It seems that electric mining equipment is all the craze right now:
Liebherr electric excavator
Caterpillar 240-ton electric haul truck
Liebherr and Fortescue partner on world’s first autonomous electric haul truck
EPCA plans to convert 50-70 mining trucks to electric power annually
Liebherr -...
Hello to everyone. I have some doubts about one problem of quantum mechanics.
My attempt.
I need to calculate the coefficient ##W_{ij}=<\psi_i | H' |\psi_j>## where ##H' = -eE(t)z## is a perturbation term in the hamiltonian and ##|\psi_i> = |\psi_{nlm}>##. We have four states and sixteen...
Suppose there is very long current carrying wire. A charged particle is present somewhere around it. The current in the wire varies with time, thus by biot-savart's law there should be time varying magnetic field. I want to know that will this time varying magnetic field produce electric field...
Hi, I wonder if someone can help with the following problem? We have a sealed box in space and inside the box is an electric motor with the stator attached to the box. The rotor arm is attached to the inner race of a bearing and the outer race of the bearing is also attached to the box.
There...
My understanding of this question is that, if you have a proton standing against a positive electric field, and move it in the opposite direction of the field, you're putting in work and therefore should have greater electric potential energy.
But that idea breaks down when you consider a...
I would like to discuss a few ways to apply derivatives in physics (I don't understand it fully). I don't need a full solution, I only need to understand how to successfully apply the derivatives
First example,
Thin insulating ring of mass M, uniformly charged by charge ##+q## has a small cut...
surfafce area = 0.502
E = -q/A2(en) = 3800
-q = 3800*(A2(en))
-q = 1.68*10^(-8)
-q = 3.37*10^(-8)
V = kq/r
V = (9.0*10^9)(-3.37*10^(-8))/0.2
V = -1519 V
I did make the problem simpler by looking at the the part from d/2 down the upper plate
here are my initial parameters I am making my size step be h since lowering it may make calculating harder
I am especially getting weird results for the field and capacitance
R = 0.1; % Radius of the...
Let's assume that we have a hollow sphere with holes at opposite ends of the diameter. What would be the field inside the hollow sphere? I know that we can look at this as the superposition of the hollow sphere without holes and 2 patches with opposite surface charge density. For some reason, in...
here is my attempted solution.
## d^2 = z^2 + \frac {L^2} {3} ##
## C ## is coulomb constant
since the point is symmetric, only the vertical component of the electric field remains. So,
$$ E = 3 E_y =3 \frac {C Q cos \theta} {d^2} $$
$$ E= 3 \frac {C Q z} {d^3} $$
thus part (a) is done ( i...
Today, I watched a video about electric field created by an infinite plate by Khan Academy. They were talking about the clever application of the Gauss's law in this case (the cylinder method), so I wondered if I could apply the same thing but to 2 plates. For example, let's say that the plates...
We take out "formulas" for electric potential from the relation
$$V=\int E.dx$$
Some general formulas are :
For a hollow sphere : ##\frac{Q} {4π\epsilon_0 x}## when x>R, x =distance of that point from the center
And the problem is we just input the distance in sums to calculate absolute...
I understand the following .a conductor is made of atoms and atoms always strive to be at equilibrium and that's why the electric field inside a conductor is zero because the electros distribute themselves in such a way so that they are in equilibrium , yet they do produce an electric field...
I have having trouble understanding Maxwell's Equations. Can anyone recommend some good book or website that can help me to understand these Equations? How can electric and magnetic fields travel perpendicular to each other? What causes electromagnetic waves to first radiate from its source? I...
The most common explanation I know is that anomaly cancelation implies the sum of electric charges of each particle must cancel generation-wise, so 3 Q(Up) + 3 Q(Down) + Q(electron) = 0, and electroweak doublets imply Q(Up) - Q(Down) = Q(neutrino) - Q(electron), so with Q(neutrino) = 0 it solves...
I tried resolving the semi infinite rods into arcs of 90 degree each placed on the three axes but that doesnt take me anywhere....
Alternatively I tried finding out the field at the point due to each rod but im unable to find the perpendicular distance from the point to the rod...I dont think...
Lambda = charge density
I tried first taking out the field due to the circular arc and I got $$ (lambda / 4π (epsilon knot) ) (2 sin (theta)) $$
For reference this is the arc that was provided in the question of angle 2(theta) and the tangent
What I dont understand is how can the fields be...
This is the general suggested approach given in a textbook.
My question is why can I not directly write it in vector form?
E1 vector + E2 vector =0 should be valid no?
Why are they choosing to write E1 mag + E2 mag=0
Then find a vector form
Then convert the magnitude equation into a vector...
Here is the exercise:
And these are my attempts:
This is for the first question about the electric field.
(I know I'm missing the drawing, which is a drawing of the plane layer of thickness 2e with a cylinder on it as a GAUSS SURFACE ).
As for the second question, I'm not sure about it, so I...
So for this problem I think I am doing something weird with the trig and/or vector components. I calculated the problem like this:
First drew a picture, q1 and q2 on the x axis. q3 located equidistant between them but negative .300m in the y direction.
First finding magnitude of Electric...
Using either H&R's Chapter 27 Example 3 or Problem 590 of the ##\mathbf{Physics Problem Solver}##, I've been unable to get the component ##E_x## or ##E_y##. There are now different angles at the charges. My thanks to berkeman for LaTeX advice, but any errors are of course my own. Thanks in...
The first image is for a conducting sheet (part of it anyway), the second is for a nonconducting sheet. Gauss' law seems to tell me that the electric field strength are different - they differ by a factor of two. Is this true?
The charge enclosed in both of them are the same, and my intuition...
Consider a negatively charged spherical conductor. On the surface of it, what is the direction of its electric field? Well, the definition of the direction of an electric field is the direction a positive test charge would go if placed at that point. But... it wouldn't move anywhere! So is the...
I have a student trying to build a simple solar powered vehicle for a high school design thinking class. He solar panel produces about 3.1 V as measured on a multimeter, but will not power the electric motor she had chosen. She tested the motor with a pair of AA batteries (2.9 V on multimeter)...
How can I find the sustaining time of an electric guitar? The influence of other components besides the strings can be neglected. I need it for my term paper.
Suppose there is an electric charge of 350 micro coulombs in space. The electric field at a distance of less than one meter will be more than 3,000,000 volts/meter considering that this field is greater than the electric breakdown of air and the charge has no place to discharge, what happens...
A recent article published in the Proceedings of the National Academy of Sciences (PNAS) describes a large electric capacitors based on carbon black and concrete. The device would be used for electric power storage - often in proximity to the electric power demand, for example, a home.
I am using an old monitor (MITSUBISHI RDT27IWLM). The power consumption changes when the screen is white or black, but does the frequency of the weak electromagnetic waves emitted from the monitor change? Or is the frequency the same, only the output is stronger/weaker?
There are two identical spheres with the same charge that are the vertices of an equilateral triangle. ##+3 \mu C## will exert an outward electric field, which is drawn in the FBD below (see the attached pic), Since the horizontal force components (1x and 2x) are equal and opposite at point P...
There are three charges with +1 μC and −1 μC, are placed at the opposite corners of a cube with edges of length 1 cm, and the distance from P to B is 1cm 2. I labeled them as A, P, and B, which is shown in the diagram below. Since we need to find the magnitude of the charge at point P and the...
How does an electric field of a moving charge, for example a moving electron, inside a wire looks like? Does it looks like this with distorted circular radial lines?
My question is specifically with calculating the intensity. The book solution is
I=P/(4*pi*r^2)
but would this not give me a weaker electrical amplitude in the final calculation after plugging it in to
I=(1/2)*√(ε0/μ0)*(E02) ?
Hi,
unfortunately, I am not sure if I have calculated the task correctly
The electric field of a point charge looks like this ##\vec{E}(\vec{r})=\frac{Q}{4 \pi \epsilon_0}\frac{\vec{r}}{|\vec{r}|^3}## I have now simply divided the electric field into its components i.e. #E_x , E-y, E_z#...
Dear Experts,
When a thin conducting sheet with no charge on is placed at a certain distance from a point charge, does it shield the electric field caused due to the point charge from reaching the other side of the sheet. As an extension of that idea, when a conducting sheet or slab is placed...