Induced magnetic field Definition and 20 Threads

Hello! I am confused about the first EM problem on http://web.mit.edu/physics/current/graduate/exams/gen2_F00.pdf (page 4, with the cylinder in a magnetic field). The solution can be found http://web.mit.edu/physics/current/graduate/exams/gen2sol_F00.pdf. In part a the solution is...

Does a ferromagnetic body moving through an external constant magnetic field obtain an induced magnetic moment? If so, can this induced field be detected? Which equation describes it? Thanks!

Homework Statement The circuit in Fig. 32-31 consists of switch S, a 12.0 V ideal battery, a 20.0 M resistor, and an air-filled capacitor. The capacitor has parallel circular plates of radius 5.00 cm, separated by 3.00mm. At time t=0, switch S is closed to begin charging the capacitor. The...

If I have some arbitrary conductor moving through a (nonuniform) magnetic field \mathbf{B}(\mathbf{r}), would the induced field in the frame of the conductor be something like: \mathbf{B}_{IND}(\mathbf{r}) = T \mathbf{B}(\mathbf{r}) where T is some diagonal matrix whose entries are related to...

Homework Statement 2. Homework Equations FB = ∫I ds×B The Attempt at a Solution My first guess was that it would not move at all. I understand that there is an induced magnetic field in the opposite direction but wouldn't the induced field produce a current counterclockwise, which, since...

What is emf in the coil? As far as I know about emf is that it is potential difference between two terminals of a source but what if it is induced in coil by changing flux linkage. What exactly happen when emf is induced?

A varying magnetic flux causes an induced voltage (according to Faraday-Lenz law) that generates a current that generates a magnetic field that generates another magnetic flux in the same circuit. Does the Faraday-Lenz law include this self induction? Or are they giving us a simplification in...

Homework Statement Two coencenteric metalic shell has inner radius $r_1$ outer radius $r_2$. We place along axis infinity wire has $\lambda$ charge in per unit length. The inner region of metalic shells inserted with relative permabilitty coefficent $\epsilon$. This system rotates with $\omega$...

Hi people, In my college laboratory we were assigned an experiment to measure the hysteresis curves of a certain ferromagnetic material at different temperatures. Sounds simple, right? Well, the block of Monel 400 we chose did something weird. We cooled it down to about -200°C and set about to...

I was reading through my College Physics text, and it talked about how NASA once swung a 20km long conductor through the Earth's magnetic field and setup a 3500V potential difference along the wire. I understand that there's no conventional current in that wire, it's not a circuit. But for a...

If the induced emf = -d(phi)/dt that is the rate at which the flux through a body is increasing, can the induced current ever be more than the actual current so as to oppose the field created? Because the rate at which the flux through a body is increasing can be greater than the flux it...

Homework Statement The problem I would like to ask is in Griffiths Introduction to Electrodynamics p358 problem 8.6 part (c)Homework Equations The Attempt at a Solution The answer is $${\varepsilon _0}EBAd\hat y$$ which is same as part (a) Here's how I found a loophole:One key information that...

Homework Statement A parallel-plate capacitor has circular plates with radius 49.0 cm and spacing 2.20 mm. A uniform electric field between the plates is changing at the rate of 1.90 MV/m/s. Find the magnitude of the magnetic field between the plates at a point 12.1 cm from the axis (entirely...

[b]1. The problem statement I'm doing a stimulation. Here is a picture of it. http://desmond.imageshack.us/Himg267/scaled.php?server=267&filename=22904502.jpg&res=medium The questions asks: when moving the voltage slider on the battery and dragging it all the way from right to left, what...

I am trying to make a crude coil gun. I remember that if I run current through a coil of wire, it generates a magnetic field according to the right hand rule. Will the inductance of the coil of wire greatly affect the strength of the magnetic field, or is it mainly due to the strength of the...

Homework Statement An electric field is directed out of the page within a circular region of radius R = 3.00 cm. The field magnitude is E = (0.500 V/ms)(1 - \frac{r}{R})t, where t is in seconds and r is the radial distance (r≤R). What is the magnitude of the induced magnetic field at a...

Hello, Say I have two concentric conducting rings, where r1 >> r2 (why is this important, btw?), and I run a time alternating current I(1) thru the larger one. This will create a magnetic field B (also) thru the smaller ring, which in turn will create itself a magnetic field B2 and so on...

I am trying to conduct an investigation based on the set up of a set of copper coils with AC ran through them to make them an electromagnet. Held above them inplace is an aluminium plate. I know that the changing magnetic field induces a current in the aluminium plate, which induces a voltage...

Hello. I am studying for my final and I can't remember how to find the induced magnetic field. I need it because, in my right hand rules handout that i must know, it says put your thumb in the direction of the induced magnetic field and you will curl your fingers into the direction of the...

I need a little help on an E&M problem I'm working on. A dielectric slab suspended in free space has a time dependant, non-uniform electric field inside of it (it was given in the problem, but I don't have it with me right now). For the material \mu=\mu_0 and \epsilon=2.56\epsilon_0. I need...