1. "A wire segment carries a current of 1.8A from a to b. There is a uniform magnetic field of 1.2T acting in the z-direction. Find the total force on the wire and show that the total force is the same as if the wire were a straight segment from a to b".
I've attached the diagram showing what...
A sphere of radius R has a unifromly distributed charge Ze inside it (essentially it's a model of a nucleus)
now my tutor worked through the first part of the question with me and we established that the potential inside the sphere was
\varphi(\mathbf{r})=-\frac{Zer^2}{8 \pi \epsilon_0...
Ok this book is very common. It's the question number 6.5
A dielectric object that has a quasi-permanent polarization when the applied field is 0 is called an electret. Consider a uniformly polarized electret in the shape of a cylinder of height h and radius 10h. The polarization in the...
Homework Statement
When a uniform electric field is applied to diamond, the induced dipole moment per unit volume (ie. polarisation) is P_{0} = 1.5 \times 10^{-7} \text{C m}^{-2}. Given that the density of diamond is 3500 \text{kg m}^{-3}, 1 kmole of diamond has a mass of 12kg. Avogadro's...
Dunno whether this is the right place for this question! but As it is related to subatomic particles, I think it is!
We know that magnetism arises due to rotation of an electron around its own axis in metals, but after all what happens due the moving electric current?
Will the same...
Hi I have tried the question below. However I am failing at the first hurdle part a! Some help and advice would certaintly be appretiated. Thanks
Taking a simple model of the hydrogen atom as an electron rotating around the nucleus in a circle or radius 0.53ee-10m at a frequency of...
Hey i was wondering about a paticular problem i found in a textbook. Specifically just one little niggle i have with it.
i am given that the electrostatic potential energy in a region of space is given by
v(r) = ((q*n)/(epsilon-0))(x^2+y^2)
(where n is a constant of dimensions m^-3)...
Hello everybody.
I would like to ask anyone who have taken graduate electrodynamics with jackson.
What do you think is the best way to prepare yourself to graduate electromagnetism by Jackson, if only electromagnetism by Griffith is covered during undergrad.
In particular, what...
Hi, got some homework to do in electromagnetism and one of the problems is:
Homework Statement
Consider a Cartesian coordinate system with charges Q (Q = 15μC) at x = + and – 1.3cm, and at y = + 1.7cm and
– 0.7cm and at z = + 2cm and -0.5cm. Calculate the flux of the electrostatic field...
does the difference in charge play a role in electromagnetism such as a +8 charge pulling a -1 being stronger because of the difference in numbers or does that even matter i mean would that mean that that is stronger compared to a + 1 charge pulling a -1 charge. Thanks in advance.
I am curious to hear people's opinions and to run a poll on the use of the term electrodynamics vs. the term electromagnetism. Which do you prefer; why? Are there instances where you would use one over the other? Etc?
To start off:
Some like the use of electromagnetism when speaking of the...
Hi, just out of curiosity...
Ampere's Law describes that an electric current produces a magnetic field. When corrected with Maxwell's displacement current, it describes that a magnetic field is also created by a time-varying electric field.
Does this mean that an electric current produces...
Homework Statement
An airplane with a wingspan W = 30 m is flying due north at v = 672 km/h. The Earth's field is 1.210-4 T, due north and inclined q = 42 below horizontal. What is the magnitude of the potential difference between the ends of the wings...
Hello, I'm new on this forum :)
I seriously need help with this problem. It has to be perfect if I want to pass the course, so I will really appreciate any solution to check my results.
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An electrical current of 100[A] runs through a cilindrical conductor (radius 0.01[m], infinite...
[SOLVED] Electromagnetism, calculate electron charge/mass ratio
I've spent all day writing a post and now I can't post a link to my picture due to your rules. Solved the problem anyway
[SOLVED] Monstrous electromagnetism question.
Homework Statement
A slope variable: thèta
Amount of coils: 10.
Cilinder:
Diameter D
Length L
Massa M
Magnetic field B.
The cilinder has 10 coils wrapped around it, in rectangular form (over the top and bottom of the cilinder). It is...
Homework Statement
An electric dipole is located at a certain distance from a grounded plane. What force does the dipole exert on the plane?
(The answer is to be expressed as an equation. No data were given, only the above text)
Homework Equations
I am not sure about this, but the course is...
I know I'm suppose to use the equation F = (kq1q2)/r^2
I tried doing [.1/sq. root (2)] m for two of the forces and just .1 m for one. I plug all the numbers into the equation and add up the 3 but it doesn't work.
I really have no clue what to do with this. Please help.
1. Feynman says all of electromagnetism follows from Maxwell equations.
2. Somebody (Pointing to a Feynman diagram of a photon/electron reaction) said all of electromagnetism is in that one diagram. So, can anyone help me with these two questions: how does point 1 come from point 2. And, how...
A complete set of lecture notes for an upper-division electromagnetism course. The course concentrates on the derivation, properties, and uses of Maxwell's equations. Topics covered include electrostatics, dielectric and magnetic media, magnetic induction, electromagnetic energy and momentum...
Could someone please recommend a book for 2nd year Electromagnetism? The topics to be covered are:
Vector calculus (div, grad, curl), electrostatics, special techniques for potentials, electric fields in matter, magnetostatics, Magnetic fields in matter, current, Ohm's law, circuits...
I've managed to derive from Maxwell's equations the homogeneous electromagnetic wave equation with respect to the magnetic field.
(The one that goes Del Squared of H minus (The second order partial derivative of B multiplied by the recipricol of C squared all equal to zero) Hopefully that...
Homework Statement
-------/\/\/\---------
I X X X 10 Ohm X X XI
I X X X X X X X X X XI
I X X X X X X X X X XAmmeter
I X X X X X X X X X XI
I--------il-----------I
...5V
Length=10cm and width =10cm
R=10 Ohms
V=5 volts
decreasing magnetic field at rate 150T/s (into the page)
What is the...
A plasma is described by the dielectric function
\epsilon (\omega) = \epsilon_0 (1-\frac{\omega_p^2}{\omega^2})
where \omega_p is a constant. Any attempt to establish a voltage
V(t) = V cos \omega t across the plasma generates a region of vacuum called the "sheath" on either side...
Hi, second term is coming up, woot. I have e&m next semester and I heard that griffiths is one of the best texts around on numberable occasions, my university has it but it's not for my class but a senior class instead. I don't see why I need to use a certain textbook, I didn't for calc or...
In A. Zee's quantum field theory in a nutshell he assumes familiarity with Maxwell's lagrangian \mathcal{L} = -\frac{1}{4}F_{\mu\nu}F^{\mu\nu} where F_{\mu\nu} = \partial_\mu A_\nu - \partial_\nu A_\mu with A the vector potential.
Although I've seen the magnetic vector potential, I've never...
Homework Statement
The atmostspheric electric fields at heights of 100m and 1000m above the surface of the eartg are 110 v/m and 25 v/m respectively and are directed downwards. Evaluate the averge electric charge per unit volume in the atmostsphere between these heights. Express your result...
Situation
A positive test charge q is moving parallel to a current-carrying wire with velocity v relative to the wire in frame S. It is assumed that the net charge on the wire is zero and that the electrons in the wire also move with velocity v in a straight line. The leftward current in the...
I read in an article that the theory of Electromagnetism makes use of Complex Numbers. How are the tools and tricks of Complex Numbers used in Electromagnetic theory. I just wanted to understand the basics of this connection of Complex Numbers and Electromagnetism and figure out if this...
Homework Statement
A proton traveling at a speed of 3.0 x 10^6 m/s travels through a magnetic field of strength 3.0 x 10^-3 T, making an angle of 45 degrees with the magnetic lines of force. What force acts on the proton?
Homework Equations
F = QvB
The Attempt at a Solution
I...
I have a few questions about electromagnetism that no matter how many texts i read i can't seem to figure out, so i'll cut to the chase.
1) why is current in the opposite direction of the flow of electrons? Shouldn't it be in the same direction as the electrons are travelling?
2) How does...
Homework Statement
Hi to everyone! I would like you to help me for a problem of classical electrodynamics. I have to study the relativistic motion of a charged particle in a coulombian field with center in the origin of the cartesian axes. I have to study the case in which the initial...
I need to make a project for my physics summative (gr 12); and I am leaning towards electromagnetism...
since my attempt in making a generator failed - and I paid a lot for the magnet and wires.
I was thinking of making http://www.bizarrelabs.com/mag2.htm
That... but then I'm wondering if...
I have one question. It is about current in conductor. It is about electromagnet induction. So I move the magnet among conductor in closed circular loop, like on this http://www.imagehosting.com/show.php/710601_untitled5.bmp.html"
So is the way of moving of the electrons depends from the way of...
Homework Statement
In problems involving electromagnetism it is often convenient and informative to express answers in terms of a constant, x, which is a combination of the Coulomb constant, k, the charge of an electron, e, and H=h/(2pi), with h being Planck's constant. For instance, the...
Hi, I've been working on a review assignment for a while, and I"m very good at electricity, so this question has me stumped.
Specifically, the 2002 AP Physics B, #3.
Two lightbulbs, one rated 30 W at 120 V and another rated 40 W at 120 V, are arranged in two different circuits.
(a) The...
If you place a metal ring in a region in where a magnetic field is rapidly alternating, the ring may become hot to your touch. Why?
Is it because a changing magnetic field can create electric fields? I AM SO CONFUSED...and it seems so simple?!?
Homework Statement
This is a question about turning effect on a current-carrying coil lying between the poles of a magnet.
Please refer to the following link:
http://img11.picsplace.to/img.php?file=img10/22/N1_000.gif
On the textbook, it is stated the turning effect on the coil can be...
Homework Statement
The figure shows a rectangular wire loop, around which a current I flows, and and an infinite straight wire. The wire lies in the plane of the loop and is parallel to, and a distance d from, the side AB. (see attachment)
Show that the amount of magnetic flux generated...
Are there any good introductory electromagnetism books that don't cost too much? I'm interested in relativity but I would like to back up and gain a more solid foundation in electromagnetism first. I would like something modern, somewhat rigourous(mathematically), and preferably with a...
Homework Statement
A particle of charge q starts from rest at the origin of coordinates in a region where there is a uniform electric field of strenth E parallel to the x-axis, and a uniform magnetic field B parallel to the z-axis.
Find the equations of motion, and solve them to show that...
Homework Statement
Two hollow concentric conducting spheres hold charges Q[1] and Q[2] as shown in the attachment.
Find the potential of each sphere, and the potential difference.
Homework Equations
Potential difference V = Phi[2] - Phi[1]
The Attempt at a Solution
I'm having...
Homework Statement
Consider a thin spherical shell having surface charge density σ, and radius a as shown in the diagram (see attachment).
Find, by integration over the sphere, the potential at a point P, a distance r fromthe centre of the sphere, for r > a. Using this result also find...
Homework Statement
A loop of wire of aream 0.32m^2 is palced in a 0.75 T magnetic field. The magnetic field is changed to 0.35 T in the opposite direction in 0.45 s . What is the magnitude of the current through the 15 ohm resistor.
Homework Equations
emf = -N (flux / time)
The...
Homework Statement
1) The coil of a moving-coil loudspeaker has a mean diameter of 30mm and is wound with 800 turns.It is situated in a radial magnetic field of 0.5T. Calculate the force on the coil, in Newtons, when the current is 12mA.
2)Explain what happens when a long straight...
In electromagnetism, when there is an emf is induced in a secondary coil from a current flowing in a nearby primary coil (such as in a transformer), then how is the mutual inductance, number of turns of each coil, the current in the primary coil, and the emf in the secondary coil related...
I'm looking for something that covers similar material to Electromagnetism, Grant and Phillips (Manchester Physics Series), but is shorter and easier to read through - I find Grant and Phillips useful (and will buy it), but could really do with a summary/outline to build on.
Any...
Hello, this is my first post on these forums, and I hope to get a response.
I am doing an experiment about building a type of an amusement park ride on a much smaller scale, and I have some questions and need some advice.
Firstly, when I make an electromagnet by wrapping a piece of metal with a...