Faraday's law Definition and 268 Threads

The drawing shows a copper wire (negligible resistance) bent in a circular shape with a radius of .5 m. The radial section BC is fixed in place, while the copper bar AC sweeps around at an angular speed of 15 rad/s. The bar makes electrical contact with the wire at all times. The wire and bar...

I was wondering about the following problem: You are looking down on a single coil in a constant magnetic field B = 0.9 T which points directly into of the screen. The dimensions of the coil go from a = 6 cm and b = 15 cm, to a* = 20 cm and b* = 19 cm in t=0.028 seconds. If the coil has...

Show that the power loss in transmission lines, PL, is given by PL = (PT)^2 X R/(V^2), where PT is the power trasmitted to the user, V is the delivered voltage, and R is the resistance to the power lines. I don't even know where to start. I am so confused by this chapter, I don't know what...

Recently I started "studying" electromagnetic induction (O.K. that might be a bit of an overstatement, but I am interested in it, so it's just as well) and I came to the following important "discoveries": - one of the Maxwell's equations states (Faraday's law if my memory serves me correct)...

Ok the question is with a U-shaped conductor and a bar that slides across. There is a battery and a switch, the switch is open for a long time then closed at t=0. I am supposed to find the velocity as a function of time. I am mostly having trouble with the integration, i know the answer but i...

I need to be enlightened on this. If a magnet with north pole facing towards a coil of wire is pushed in does it induce a current clockwise, or counterclockwise? If you push the coil in towards the magnet will it induce current in the opposite direction? How can I use the right hand rule with...

A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.60 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 x 10-2 ohm/m. What is the average electrical...

So I'm studying for my physics final, and I ran across a problem that is giving me a bit of trouble. http://cyclotron.tamu.edu/dhy/sample_final_exam.pdf the question is 3b. I'm thinking that the wire loop will have no induced current in it since there isn't a change in flux when you...

Faraday's law of induction is emf = - (d/dt) ∫S B∙da . When the closed loop (serving as the boundary of the surface S) is independent of time, the above relation is equivalent to the Maxwell equation curl E = - ∂B/∂t . However, when the closed loop C (i.e. the boundary of S) is...

Induced emf around a closed path in a time-varying magnetic field. A magnetic field is given in the xz-plane by B=Bo*cos(pi)(x-Uot)ay Wb/M^2. Consider a rigid square loop situated in the xz-plane with its vertices at (x,0,1), (x,0,2),(x+1,0,2) and (x+1,0,1). 1.What is the expression for the...

The generator of a car idling at 950 rpm produces 12.4 V. What will the output be at a rotation speed of 2500 rpm assuming nothing else changes? I'm guessing that is easier and I'm looking to make it harder. I can't find anything in my textbook involving rpm. I'm thinkin to use this...

So we were going through Faraday's Law today in class: \int\vec{E}\cdot d\vec{l} = -\frac{d}{dt}\int\vec{B}\cdot d\vec{A} Mathematically I'm fine with it, however, is there any good physical way to explain it, it seems very odd that if you had a field such as: \vec{B} = B_0cos(\omega...

A constant magnetic field passes through a single rectangular loop whose dimensions are 0.348 m x 0.593 m. The magnetic field has a magnitude of 2.26 T and is inclined at an angle of 66.0° with respect to the normal to the plane of the loop. (a) If the magnetic field decreases to zero in a time...

A closely wound, retangular coil of 80 turns has dimensions of .25m x .4 m. The plane of the coil is rotated, in .06 sec from a position where it makes an angle of 37 degrees with a magnetic field of 1.1T to a position perpendicular to the field. What is the average emf induced in the coil...

Hello there, I'm new to this place, I thought these forums looked like a wonderful source of knowledge, so purhaps some of you could be so kind as to help with the following problem...? (here's hoping I'm in the right forum for a start...) sorry about the length of it, but i did draw a...

Why is it that a changing magnetic flux through a surface should induce an emf? I know that the emf is from a non-conservative electric field, but how exactly was this field generated? (if that is the correct expression for it)

I can't seem to wrap my head around this question. Any help would be great. A coil consists of 20 turns, with a 10cm radius (all turns are uniform). It rotates uniformly around the z-axis at an angular speed of: w=20 rad/s A uniform magnetic field passes along the x-axis with a magnitude...

I'm having trouble with the following problem: A bar of mass m, length d, and resistance R slides without friction on parallel rails. A battery that maintains a constant emf E is connected between the rails, and a constant magnetic field B is directed perpendicular to the plane of the page...