In physics (specifically in electromagnetism) the Lorentz force (or electromagnetic force) is the combination of electric and magnetic force on a point charge due to electromagnetic fields. A particle of charge q moving with a velocity v in an electric field E and a magnetic field B experiences a force of
F
=
q
E
+
q
v
×
B
{\displaystyle \mathbf {F} =q\,\mathbf {E} +q\,\mathbf {v} \times \mathbf {B} }
(in SI units). It says that the electromagnetic force on a charge q is a combination of a force in the direction of the electric field E proportional to the magnitude of the field and the quantity of charge, and a force at right angles to the magnetic field B and the velocity v of the charge, proportional to the magnitude of the field, the charge, and the velocity. Variations on this basic formula describe the magnetic force on a current-carrying wire (sometimes called Laplace force), the electromotive force in a wire loop moving through a magnetic field (an aspect of Faraday's law of induction), and the force on a moving charged particle.
Historians suggest that the law is implicit in a paper by James Clerk Maxwell, published in 1865. Hendrik Lorentz arrived at a complete derivation in 1895, identifying the contribution of the electric force a few years after Oliver Heaviside correctly identified the contribution of the magnetic force.
Homework Statement
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In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l,w and d, respectively.
A uniform magnetic field B is applied on the strip along the positive...
Homework Statement
Rigid contour of an isosceles triangle and a long line cable lie in a plane and are located in vacuum . Determine the intensity of the magnetic force F acting on the loop. Current I = 100 A.
free upload image
Correct answer:
F = 386 mN.
I am getting 2 mN.
Notice that I...
Why is the force on a particle perpendicular to the magnetic field? In electric and gravitational field, the force is in the direction of the field. Is it due to the fact that electric and magnetic waves in electromagnetic waves oscillate at right angles to each other, or something else?
I decided to simulate this scene in Lord of the Rings for a project in school with the purpose of calculating the "real" mass of the One Ring. I've done the experiments according to this principle sketch but I have some troubles with calculating the magnetic force that the copper coil is...
Homework Statement
Homework Equations
The Right-Hand Rule
The Attempt at a Solution
I'm having some issues with the right-hand rule to find the direction of magnetic force, and I'm doing a homework problem.
The answers I got are (letters are vector directions):
A: -j
B: i
C: j
D: i
E:-i...
Hello all, new here but plan to stick around for a while. I am currently trying to make a sensor that can detect if a material below it is paramagnetic. I believe paramagnetic is the proper term, but it needs to detect if the force exerted by permanent magnet is above a certain threshold. The...
[Split off from this thread]
I think that the force is always repulsive. I think that an electron would have to travel faster than c for it to become attractive.
Mod note: After merging posts from a duplicate thread, the time stamps put the posts in the incorrect order.
The original question was,
Field strengths aren't measured in joules, so I don't think your question can be answered.
PS If your name isn't "Brian Green" you might find another one...
So, a friend asked me this question in school and I've come up with an answer, I'm just not sure that it is right.
Say you have a charged particle moving perpendicular to a magnetic field. There will be a force acting on it given by F=qvB.
Now suppose your'e moving along at the same velocity as...
I'm reading how a charged particle moving through a magnetic field experiences a force (called magnetic force).
I understand that it moves the particle in a certain direction and because the greatest force is experienced when the magnetic field is perpendicular to the particle's velocity vector...
Faraday's law is
$$\nabla \times \mathbf{E} = - \frac{d\mathbf{B}}{dt} $$
If we let our time dependent surface be ##\Sigma(t)## and its boundary ##\partial \Sigma(t)##, then by Stokes' theorem
$$ \oint_{\partial \Sigma(t)} \mathbf{E} \cdot d\boldsymbol{\ell} = - \int_{\Sigma(t)} \frac{\partial...
The work done by magnetic force, F=qv\times B, is zero. Can we infer that the magnetic force is conservative? If so, how can we show that \nabla \times F=0 ?
Homework Statement
An electron moves in a straight line at a speed of 6.0 \times 10^7m/s. Calculate the magnitude and direction of the magnetic field at a position 0.005m behind the electron and 0.015m below its line of motion.
Homework Equations
F=qv \times B
The Attempt at a Solution
I'm...
Hi, I've been struggling on this homework problem for quite a few hours now and would really appreciate a pointing in the right direction. It's a fairly entertaining problem that I'm getting stuck on in several places.
1. Homework Statement
The problem goes:
"An erratic engineer, who lives in...
Hello! I just need someone to check my work here. I already turned in the homework with my hunch, but now I just want to check my work because it is killing me not knowing 100% :) I am having strong conflicting thoughts on particular parts and thought I'd post it here for clarification. I will...
Homework Statement
A straight wire (length Lcm, mass mg) lies horizontally on top of a sensitive scale. The wire is oriented so it runs north-south, and it is part of an electric circuit that includes a battery and an open switch. There is a uniform magnetic field everywhere, magnitude bT and...
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i'm doing a little research and in need of help since I'm not so talented in physics.. :(
Is it possible to attach 2 cars with magnetic force so that they can be driving as one? (one car in the front and another car behind)
I think it can be done with magnetic force but how..
Also, Is it...
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I'm new to the forums but I had a problem I was trying to solve that I could use some help. Hoping someone here could point me in the right direction.
Imagine you have two (2) cylindrical magnets that are diametrically magnetized. Both magnets are of equal size and magnetic strength...
Hi!
I have performed an experiment measure force on a wire with electric current in a magnetic field. I got 3 graphs: Force as function of length (L) of wire, Force as function of current (I) and Force as function of magnetic field (B). In all cases, I got approximately a straight line through...
Imagine an infinitely long wire carrying current i1 in west to east direction. At a small distance 'd' above the wire there is another small current carrying wire of length 'l' carrying current i2 from east to west direction (opposite to the direction of current in the below placed wire)...
Homework Statement
An electron (charge = –1.6 x 10^–19 C) is moving at 3.0 x 10^5 m/s in the positive x direction. A magnetic field of 0.80 T is in the positive z direction. The magnetic force on the electron is:
http://edugen.wileyplus.com/edugen/art2/common/pixel.gif
a) 0 N
b) 3.8 x 10^–14...
Homework Statement
A square loop PQRS carrying a current of 6A is placed near a long wire carrying 10A as shown in the figure. Find the magnetic force on the square loop.
Homework Equations
F = B * i * l ...... (1)
B = (µ0 * i)/2 π r
The Attempt at a Solution
I tried finding out the...
I'm wanting to know the force between two wires carrying current but I think I did something wrong when I calculated it. Here is my working.
I got a value of 0.0021365 ohms for both wires from http://chemandy.com/calculators/round-wire-resistance-calculator.htm
1000 volts pass through the...
Homework Statement
A coil of 25 turns of wire is suspended by a thread. When a current flows through the coil, the tension in the thread is reduced by 4.0 ´10-2N.
http://members.shaw.ca/barry-barclay/Self-Tests/test11/Magnet20.gif
Homework Equations
F=IBL
B=nμI[/B]The Attempt at a Solution...
Hey all!
I have a question about induced voltage and magnetic force "acting together". What I mean is that I know that when there is a perpendicular magnetic field acting on a wire that has current going through it, it will produce a magnetic force perpendicular to both magnetic field and...
Homework Statement
The robot crawler has a magnet attached to it. The idea is to get the crawler up the wall.
What is the magnetic force required to hold a object (in this case) a robot crawler with an attached Magnet?
Is more magnetic force required to hold the crawler while it goes up the...
I have been reading ahead in my course from Griffiths textbook and I have a couple of questions. I found this solution online to a question: http://glennrowe.net/physicspages/2013/09/23/balancing-magnetic-force-with-gravity/
It says: A square loop is cut out of a thick sheet of aluminum. It is...
Homework Statement
A 2.60-N metal bar, 1.50 m long and having a resistance of 10.0 Ω, rests horizontally on conducting wires connecting it to the circuit shown in the figure(Figure 1) . The bar is in a uniform, horizontal, 1.60-T magnetic field and is not attached to the wires in the circuit...
Homework Statement
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A circular loop of wire, of radius r, carries current I. It is placed in a magnetic field B whose straight lines seem to diverge from a point a distance d below the ring on its axis. (That is, the field makes an angle θ with the loop at all points, where tan(θ) = r/d.)...
Homework Statement
A particle of mass M and charge Q>0 moves in a region of space where the magnetic field has a constant magnitude B and a downward direction. What is the magnetic force on the particle at an instant when it is moving horizontally toward the north with a speed v?
(a) QvB...
There are plenty of examples where someone derives the magnetic force from a current carrying wire on a moving charged particle by looking at the frame of the particle and finding that the current has Lorentz contracted in such a way as to produce an electric field in an otherwise neutral wire...
Homework Statement
Turns of wire would around a toroidal core, carrying a sinusoidal alternating current i(t), represent a toroidal coil in my case. My question is, does magnetic force affect a non-moving charge outside of toroidal core and is there a magnetic field outside of toroidal core...
Homework Statement :
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Three parallel wires of length l each carry current i in the same direction. They’re positioned at the vertices of an equilateral triangle of side a, and oriented perpendicular to the triangle.
Find an expression for the magnitude of the force on each wire.
Express your...
Consider a line charge with charge density λ and a electric charge q. A coordinate system moving at velocity v ,it will see the line charge as a current ,and the electric charge(which is also moving seen from the moving coordinate system) will feels magnetic force. Why does this happens?
Homework Statement http://www.sumoware.com/images/temp/xzlknterambqmokp.png
How to calculate the Magnetic Force of THE "Right Triangle" influenced by a Line
when the magnetic field isn't constant B=u0*I/2piR?
Homework Equations
B=u0*I/2piR
F=iLB
The Attempt at a Solution
I can use F=iLB to...
Would it be possible to have a generalised equation for magnetic force of interaction between magnet-magnet and magnet-ferromagnetic materials maybe iron.
A warm greeting to all reputed members of physicsforum.com.
I'm an undergraduate student. I'm trying to create a mathematical model for calculation of force of interaction between two identical bar magnets and force of interaction between a magnet and a steel disc.
If I go with standard formulae...
Homework Statement
A wire carrying 1.5 A passes through a region containing a 2.0 T magnetic field. The wire is perpendicular to the field and makes a quarter-circle turn of radius R= 1/ as it passes through the field region as shown below. Find the magnitude and direction of the magnetic force...
I'm just really confused with this right hand rule even though it seems like it's supposed to be pretty simple and obvious. I know the rules, however it doesn't really work for me. Maybe I'm doing something wrong. I have three examples I'd like to cover which are related to each other, I hope...
Problem:
The figure shows a region of uniform magnetic field out of the page. Outside the region, the magnetic field is zero. Some rectangular wire loops move as indicated. Which of the loops would feel a magnetic force directed to the right?
Attempted Solution:
By right hand rule none of...
Homework Statement
A particle with charge q moves with velocity v near a long, straight wire which has a current I flowing through it which generates magnetic field B. Give an expression for the magnitude of the force on this particle in terms of q, v = | v | and the magnitude of the magnetic...
Homework Statement
A circular coil with center on the z axis and orthogonal to the xy axis carries a current. The coil is in a magnetic field B with axial symmetry compared to the x axis. B forms an angle θ with the z axis. Calculate the magnetic force acting on the coil.
2. Homework...
Hello, I'm new here but I think this is the correct place to post this topic but please let me know if I am incorrect.
Question:
Does magnetic force transfer weight? For example: If you have one magnets negative side being lowered onto the positive side of another, they would repel. So now you...
Hi,
Suppose I perform a basic experiment of an elastic collision between 2 carts. I do not want the carts to touch each other so I adjust a permanent magnet to each cart and give each one a starting velocity. Carts get close to each other, kinetic energy is transformed into "potential magnetic...
1. Wire 1 is oriented along the y-axis and carries a current I1. A rectangular loop located to the right of the wire in the xy-plane carries a current I2. Find the magnetic force exerted by wire 1 on the top wire of length b in the loop labeled "Wire 2" in the figure.2. F = IL x B
3. Attached...
In doing a science project using the gauss rifle we changed the number of magnets side by side verses aditonal stages, The result was the ball traveled a shorter distance the more magnets used. I understand why this occurred but need scientific reason and explanation based on what laws of...
Homework Statement
Considera 1.0 C charge moving with a velocity of v = -2.0i + 2.0j - 1.0k in a magnetic field of B = -4.0i + 1.0j – 3.0k.
What force is this charge experiencing?
What is the angle between the velocity and magnetic field vectors?
Homework Equations
F = q(E + v x B)...
Not necessarily a homework question but this is pretty fundamental. I can't get a decent derivation online.
If the length of the wire in the uniform magnetic field is l and it moves a distance \delta s in \delta t:
From the Lorentz Force Law:
\vec{F} = q\vec{v}\times\vec{B}
if flux...