Induced Definition and 977 Threads

I have got a doubt regarding the situation when a ring rolls in a non-uniform magnetic field. We can see that the flux linkage is increasing (considering dB/dt to be positive). So EMF should be induced in the loop. But if we join any two points, say the instantaneous axis of rotation and the...

Hi, What if the inductor coil is wound one way rather than the other. Then the circular flow of current will be clockwise in one case and anticlockwise in the other. And if the inductor is connected to an ac source, then the current will vary. Now in both the orientations, the variation...

How would one go about finding the EMF induced when a two-turn coil of wire is straightened into a one-turn coil?

Homework Statement A coil with 10 windings(radius 0,07m) is inside a homogenous magnetic(B=0,050T) field, it makes an angle of 90 degrees with the field lines so the magnetic flux is at it's max. Over a period of 0,050 seconds it gets turned by 180 degrees, what is the average induced...

I'm doing a lab write-up for physics 2. The experiment is about the title, a bar magnet being dropped through a solenoid. I have to explain four graphs that plot the change in emf (y axis) vs. time (x) axis. There are incoming and outgoing peaks on these graphs. I have to tie these results...

I'm doing a lab write-up for physics 2. The experiment is about the title, a bar magnet being dropped through a solenoid. I have to explain four graphs that plot the change in emf (y axis) vs. time (x) axis. There are incoming and outgoing peaks on these graphs. I have to tie these results...

I am sorry please delete this post if it has been already asked Light is an electromagnetic wave right? i haven't have ever heard of light distorting or causing disturbances in antenna signal,why is it so isn't it also an electromagnetic wave?

Homework Statement A square circuit with side L lies in the x-y plane, is centred on the origin and has sides parallel to the x and y axes. At time t=0 it starts turning about the x axis, in a region characterised by a uniform magnetic field B parallel to z, with uniform angular speed omega...

hi gang, Just building a seismometer I have 2 x 2.5cm disc rare Earth magnets spaced far enough apart for a coil of wire to move between them. Would you expect there to be any difference in induced voltage into a coil between 2 magnets when the magnets are orientated to attract or repel ...

Hi everyone, This question is bothering me for days and would hope to receive some help in this forum. This question is with regards to Faraday's law on EMI. Will an emf be induced when a copper rod is accelerated between a uniform magnetic field? My answer would be no if the rod has...

Electricity affect neurons. For example, in 1791 Galvani made the legs of a dead frog twitch by exposing them to a spark, and more recently in history, electric currents through the brain has been used to deliberately induce "therapeutic" epileptic seizures. What I wonder about is the exact...

Homework Statement Attached below Homework Equations Emf = - \Delta\Phi / \Deltat emf = vBl; motional emf The Attempt at a Solution In the two attached files, there are problems that ask for the direction of the induced current. I understand that the induced current flows in the...

I'm sure most of you on this board know what the VASIMR plasma rocket engine that is being prepared to be tested on the ISS. I read that high-powered radio waves are used to heat the argon gas to the plasma state of matter and then the superconducting magnets eject the superheated gas out of the...

Homework Statement A square wire loop of dimensions L X L (L = 15.5 cm) oriented in the xy-plane and centered on the x-axis enters a region where the magnetic field (B = 0.855 T) is first oriented in the +z- and then in the -z-direction as shown in the diagram below. (Note: W = 15.501 cm and...

Homework Statement A circular metal ring, as shown on the diagram below, is constructed so as to expand or contract freely. In a region with a constant magnetic field Bo oriented perpendicular to it, the ring expands, with its radius growing with time as r=r0(1+\alphat2). As the ring expands...

Hi Forum! I have got a question about the induced scalar potential. I will present the problem from beginning. Lets say we have a Poisson's equation in form: \epsilon \nabla^2 \phi = -4\pi \varrho(r,t) where \epsilon is the dielectric constant. By use of the Fourier transform...

Homework Statement 1. compare the induced voltage of the attached magnet ( two like charges) with the induced voltage of one magnet only? 2.compare the induced voltage of attached magnet (opposite poles) with one with only one magnet Homework Equations The Attempt at a...

Hi everybody It's easy (and well known) to calculate the charge distribution of a condutor in the presence of a point chage. BUT if we change this point charge and put an charge distribution... like a condutor disc, how can I calculate the induced chage of the other conductor?? THANKS

A positive charge Q is located at a distance L above an infinite grounded conducting plane. What is the total charge induced on the plane? (A) 2Q (B) Q (C) 0 (D) -Q (E) -2Q I know the answer is C, but why? Thanks a lot!

Homework Statement "You push a rectangular loop of width .2m, length .8 m, and resistance R=200\Omega into a magnetic field (out of page) Bout=.4 T and a speed v=.2 m/s. The long side of the rectangle is parallel to the x axis. What is the current flowing in the loop?" Homework Equations I...

Homework Statement What is the induced magentic field inside the coil? Attached image shows the coil and direction of rotation. Homework Equations Right hand rule of some sort. The Attempt at a Solution Not sure what hand rule to use to find the induced field in the coil. What...

My classmates had an argument. There are 2 trolleys; one of them (A) is attached to a solenoid wrapped around a soft-iron core, which is connected to a d.c. circuit. There's another trolley (B) which is attached to a solenoid wrapped around a soft-iron core but it is connected to a load...

Homework Statement Find the induced emf in a rotating disc of radius (a) in a magnetic field (B), rotating with uniform angular velocity (w). If the disc is replaced by a rotating conductor of length (a) fixed at one end find the induced emf in the conductor. 2. The attempt at a solution...

I am beginning to read about the topology, I met a problem puzzled me for a while. If Y is a topological space, and X\subset Y, we can make the set X to be a topological space by defining the open set for it as U\cap X, where U is an open set of Y. I would like to show that this indeed...

A hypersurface of Euclidean space obtains its Levi-Civita connection by orthogonal projection of ordinary derivatives of vector fields in Euclidean space onto the hypersurface's tangent space. Suppose rather than the unit normal, there is a non-zero transverse vector field and orthogonal...

Homework Statement We have a solenoid with current I and n turns per unit length and (neglecting hysteresis) a ferromagnetic core. Find B and H. Show that when I is varied an electric field is induced and draw it on a diagram. Homework Equations \nabla \times E = - \frac{\partial...

Homework Statement A rectangular conducting loop of dimensions l×w and resistance R rests in the plane of a long straight wire as shown. The closest edge of the loop is a distance a from the wire. The current in the wire is in the upward direction and increases at a constant rate from I to...

Homework Statement A circular coil of area A with N turns rotates at an angular velocity w about an axis perpendicular to its own axis and to a uniform magnetic field B. Find an expression for the induced EMF in the coil in terms of B, N, A, w and time t. What is the orientation of the coil...

Homework Statement Salutations, all. I'm trying to show that if T_A is ergodic, then so is T . This was an iff, and I have the other inplication. I'm a little lost with how to proceed, so any help would be appreciated! Homework Equations T(X, \mathcal{B}, m) to itself is an...

At first I thought an induced ion dipole only applied to non-polar molecules, but in the textbook it says it polar molecules are affected by induced ion-dipole forces as well ("for the polar molecule, it enhances the dipole moment already present", Silberberg) ? If that's so, does that mean that...

Homework Statement This is a question from the Princeton Review of AP physics B, 2011 edition. A small circular loop of wire (radius r) is placed on an insulating stand inside a hollow solenoid of radius R. The solenoid has n turns per unit length and carries a counterclockwise current I...

If I have a B field in between two current carrying sheets and I approach this moving at a constant speed. And I have an electron in my hand, when I see the electron move will I say it moved because of an induced E field? Or If I am standing by the plates and I see the electron move into the B...

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 Parallel plate capacitor with circular plates with radius of 26mm and a plate separation of 6mm. A sinusiodal potential difference is applied across the capacitors plates with Vmax = 170V at a frequency of 60Hz. 170sin(2*pi*60Hz*t) Homework Equations V = ∫E∙dl = El (l...

I know the equation for emf: -dflux/dt= -dB/dt*A . In my case everything is constant accept the magnetic field and I am unable to find the equation for that. I know that is what dB is for but that simply does not work in this case. What is the equation for induced voltage, when everything is...

Hi I am reading Griffiths EM book and I have some questions about the induced surface charge from chapter 2 and 3. In chapter 2 , he says that \frac{\partial V_{above} }{\partial n}- \frac{\partial V_{below} }{\partial n} = - \frac{\sigma}{\epsilon_o}...1) which is alright. Now...

Homework Statement A circular conducting coil with N=100 turns and radius "r" is oriented in the xy plane. The leads of the coil are connected to a circuit with resistance "R." A time varying external magnetic flux density "B" is applied along the z-axis. What is the total magnetic flux...

Say I have a closed metal rectangular shaped wire in a region with a magnetic field. If the magnetic flux is constant, there is no induced current, no experienced force, and no EMF? If I start the changing the magnetic flux, I suppose by increasing the magnetic field, there will be an...

Homework Statement Uniform time varying magnetic field \vec B_{(t)} pointing at z direction, filling up a circular region on xy-plane. Find the induced E field. I tried two different ways and get two different answers. Please tell me what did I do wrong. Homework Equations Emf...

1. The problem. A circular loop of radius 4cm has a plane which is perpendicular to the electric field B. (The area vector is +k, so is the field vector.) The strength of the field varies with time according to the equation B=4/(t^3). Give an expression for the voltage as a function of time...

Homework Statement A bar magnet is spun at constant angular speed w around an axis as shown in Figure P31.38. A stationary flat rectangular conducting loop surrounds the magnet, and at t = 0, the magnet is oriented as shown. Make a qualitative graph of the induced current in the loop as a...

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...

Hi there, If a proton passes through a loop of wire, it induces a tiny current in the wire. Will the proton lose energy and slow down as a result of this? If so, by how much?

I am taking a few medications that have *nightmares* listed as the main side effects. I am having a lot of nightmares. What could cause this? How could the medication change normal dreams into nightmares? Wouldn't nightmares be different for each person? I now have dreams that range...

Homework Statement The square loop in the figure below is made of wires with a total series resistance of 10.0. It is placed in a uniform 0.100 T magnetic field directed perpendicular into the plane of the paper. The loop, which is hinged at each corner, is pulled as shown until the...

Homework Statement Hey guys, This is just a qualitative question. So assume I have a massive super large magnetic field, and pull a straight, isolated conducting wire sideways through it with constant velocity. I know that the EMF induced is given by emf = Blv where l is the length of the...

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...

Apologies if this is not in the proper location/format/etc; first post. In a very short (3 min) segment on MythBusters, they unsuccessfully tried to induce a current in a loop in the same plane as a current carrying wire (AC). I originally assumed this didn't work because the B field was not...

Please note, I'm not in school anymore -- just a basic physics question! Homework Statement A conductor is placed inside the coil of an induction heater. Imagine that the inductor coil has radius R, number of turns N, operating frequency f [Hz], drawing current I = I0 * sin(2*pi*f*t). The...

Homework Statement I have a few homework questions that ask for the direction of induced current for ex a loop of wire. I can't figure out how to find it .