What is Induced electric field: Definition and 42 Discussions
In physics, photon-induced electric field poling is a phenomenon whereby a pattern of local electric field orientations can be encoded in a suitable ferroelectric material, such as perovskite. The resulting encoded material is conceptually similar to the pattern of magnetic field orientations within the magnetic domains of a ferromagnet, and thus may be considered as a possible technology for computer storage media. The encoded regions are optically active (have a varying index of refraction) and thus may be "read out" optically.
Faraday's law tell's you about the line intergal of the electric field, but you have to know the direction of the induced electric field first in order to properly apply it. How can I find its direction? Is it in the same direction as the induced current?
The problem is shown above, the hint to solve the problem is below. See the hint if it is difficult for you to imagine what is going on.
I am assuming the diagram in the hint shows what's happening when the mass is falling at terminal velocity. I have quite a few questions.
1. How do the wheels...
I have drawn a picture of what the induced electric field will look like, and I have determined its magnitude both within and outside of the magnetic field. I was able to get the right answer for part (b) with this information, but I don't understand why the answer for part (c) is 0 J. It...
Let’s say we have a right handed Cartesian system and magnetic field goes in positive z direction, and let’s assume that the magnitude of magnetic field varies with time.
Now, if I draw a circle with radius ##r## in the ##x-y## plane and let the magnetic field pass through it and vary with...
The Faraday's law and Lenz's law together give you, $$\xi = -\frac{\partial\phi_B}{\phi t}$$ or put another way,$$\vec{\nabla} \times \vec{E} = -\frac{\partial \vec{B}}{\partial t}$$. My question, I am just asking to make sure, the spatial dependence of ##\vec \nabla \times \vec E## will be the...
If there is a very very big(infinitely big) region of space where ## \frac {dB} {dt} = constant ## what would be the E field at any point? Obviously ## \nabla x E = constant ## but what after that ?
Homework Statement
Homework EquationsThe Attempt at a SolutionThe emf gets induced due to the changing flux.
The flux through the rod remains 0. So, there is no induced emf.
I don’t know how to calculate induced electric field.
But as there is no induced emf, so there is no induced...
Homework Statement
This is irodov's problem #310 in electrodynamics
A long solenoid of cross-sectional radius a has a thin insulated wire ring tightly put on its winding; one half of the ring has the resistance ## \beta ## times that of the other half. The magnetic induction produced by the...
Homework Statement
A thin and straight metallic rod of length L is rotating about its middle point with angular velocity ##\omega## in a uniform magnetic field B. The axis of rotation is perpendicular to the length of the rod and parallel to the magnetic field. The strength of the induced...
In class we were trying to calculate the induced electric field created by changing the magnetic field stregth.
Imagine there's a circular surface which magnetic field out of the screen.Since we are changing the magnetic field from Faraday's Law there should be a induced current or charge flow...
If a time varying magnetic field exists in vertically downwards direction in a region A, an electric field is induced in the direction perpendicular to it i.e. in horizontal plane. How to find the direction of the E field in the horizontal plane?What factors decide the direction of the E field...
Homework Statement
In the below figure, magnetic field is decreasing at a rate of 1.5T/s in a circular region of radius 2m. EMF developed in the rod will be?
Homework Equations
$$V_{\text{induced}}=-A\frac{\mathrm{d}B}{\mathrm{d}t}$$
The Attempt at a Solution
I tried using induced electric...
Hi everyone,
I just wanted to know/understand that, why do the dielectrics don't get polarized, when subjected to induced electric field ?
Because, according to the definition of electric field(which is a vector), it is the force per unit charge, which implies, that electric field has a unique...
Homework Statement
Charge Q is uniformly distributed on the rim of a thin insulating disc of mass m, radius R, which is initially at rest and placed on a smooth horizontal surface. What will be the angular velocity of the disk if a magnetic field B, perpendicular to the plane of the disk, is...
Let's say I place two different size conducting loops inside of a uniform magnetic field. For the sake of the diagram I have the loops share a point, but just treat them as though they are not touching.
Then I decrease the value of the magnetic field very quickly.
\frac{dB}{dt} =...
Imagine there is a hollow toroidal conducting chamber and a long solenoid in the middle. When we power the coil, does the induced electric field "propagate" inside the chamber? My prediction is that the changing flux will cause induction regardless of the cage.
Thank you.
Homework Statement
An infinite wire carrying a constant current ##I## in the ##\hat{z}## direction is moving in the ##y## direction at a constant speed ##v##. Find the electric field, in the quasistatic approximation, at the instant the wire coincides with the ##z## axis. [Answer...
Homework Statement
Imagine a uniform magnetic field, pointing in the ##z## direction and filling all space (##\vec{B} = B_0\hat{z}##). A positive charge is at rest, at the origin. Now somebody turns off the magnetic field, thereby inducing an electric field. In what direction does the charge...
Suppose there is an uniform magnetic field along z-direction. Now someone turns off the field. Then there will be an induced electric field.
Can anybody draw this induced electric field lines?
I know the electric field will curl around. But where will be the centre of that curl.
Do the electric...
Homework Statement
The problem give is: A solenoid has N=500 windings, radius a=.1 m and a height h = .6m; the current is found to be decreasing according to I(t) = Io - bt, where Io = .4 amps and b = .2 amps/second.
Calculate the rate at which electromagnetic energy is leaving the solenoid...
Inside of circular region of radius 10cm shown in Figure 5(a) there is
a uniform magnetic fi eld pointing upwards and three protons held in
place: one at the center, one at a distance of 5cm from the center and
one at a distance 15cm from the center e there is no magnetic field.
The...
Homework Statement
https://www.writelatex.com/628580dnzrxr#/1303752/
The Attempt at a Solution
As I said in the link above I tried using the surface orthogonal to the cross section of the wire of radius to integrate.
For the line integral I assume it just reduces to E*2(pi)R but for...
I am having a bit of trouble understanding something in my textbook and was wondering if you guys could help clarify.
We just learned Faraday's Law that a time variant magnetic field will enduce an emf in a coil. What my textbook says is that " The electric field in the loop is NOT...
As part of a Griffiths problem, I have a charged capacitor placed in a uniform magnetic field which points in +x direction. the capacitor plates are parallel to xy planes. Suddenly, the B field starts decreasing in magnitude...what is the direction of the induced E field?
It makes most sense...
Assuming there is a time varying magnetic field (B) , how to determine the direction of the induced electric field due to B. and to which parameters does it depend?
When you use Faraday's law to calculate the induced electric field due to a changing magnetic flux, you integrate over a loop defined by the circuit you're interested in.
Why is the electric field confined to the circuit? Couldn't I just pick a random loop in space and integrate over that...
Homework Statement
A long solenoid with 1000 turns per meter and radius 2cm carries an oscillating current given by (5A)\sin(100\pi t). What is the electric field induced at radius r=1cm from the axis of the solenoid? What is the direction of this electric field when the current is...
Can electric field be induced at a point near a time varying uniform magnetic field? "Near" means not the in the place where magnetic field exist. But at a point outside the field's presence.
Hi everyone,
From what I understand if you had a time varying magnetic field inside a dielectric it will induce a time varying electric field according to Faraday's Law:
\nabla\times\mathbf{E}=-\frac{\partial \mathbf{B}}{\partial t}
My question is will the dipoles in the dielectric then...
So I just had an exam and I'm so unsure about this problem. It seems that I got it right, but I could be completely wrong. XD
Homework Statement
A long, straight current-carrying wire carries an increasing current I that is uniformly distributed over the cross-section of the wire (the...
Homework Statement
In a cylindrical region of radius R, there exists a time varying magnetic field B such that dB/dt=k(>0) . A charged particle having charge q is placed at the point P at a distance d (> R) from its centre O. Now, the particle is moved in the direction perpendicular to OP (see...
Homework Statement
This is not really a question, just a concept I am trying to understand. I understand changing magnetic field induces an electric field - but how does it do this?
Homework Equations
The Attempt at a Solution
I figure since the changing magnetic field would...
If a time varying magnetic field of infinite dimensions crosses a plane at right angles what can we expect induced electric field lines to look like? Straight lines with direction determined by the right hand rule?
I am a high school student, so forgive me if my question appears stupid.
Consider a uniform magnetic field normal to the plane of the screen with varying magnitude. consider a point P on the screen in the magnetic field.the varying magnetic field will induce an electric field, with the field...
The whole idea of an electric field induced due to a changing magnetic flux seems to run wildly counterintuitive to me. Consider this set up as shown in my physics textbook. A current carrying solenoid placed along the axis of a circular conducting loop. A changing current through the turns of...
I've just seen induced electric field concepts. Could anyone provide a link, which explains it?
I had some rather stupid doubts regarding it:
1.If a circular conductor is placed in a varying magnetic field, then to find the induced electric field, we take the center of the conductor as...
Homework Statement
Please see the attached figure. We have two parallel long wires carrying a time varying current I(t), but running in opposite directions. We wish to know the induced electric field between the wires, but only in the plane containing the two wires.
Sorry that I don't know...
Homework Statement
An atomic electron (charge q) circles about the nucleus (charge Q) in an orbit of radius r; the centripetal acceleration is provided, of course, by the Coulomb attraction of opposite charges. Now a small magnetic field dB is slowly turned on, perpendicular to the plane of...
Hi there.
On my electromagnetism test there was the following question:
A long solenoid with radius R has N turns per unit length and carries a current I = I_0*cos(ωt)
Find the electric field inside and outside the solenoid.
I got the following solutions:
\vec{E} = \frac{\mu}{2} N...
Hello, I'm stuck (again) on a physics problem.
The problem:
Early in 1981 the Francis Bitter National Magnet Laboratory at M.I.T. commenced operation of a 3.3 cm diameter cylindrical magnet, which produces a 30 T field, then the world's largest steady-state field. The field magnitude can...