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
A rectangular loop of wire 1.00 m wide and 1.50 m
long has a mass of 0.150 kg and a resistance of
0.750 Ω. The loop falls out of a large region of
uniform horizontal magnetic field, as shown, having
reached a terminal speed of 2.00 m/s.
Homework Equations
None...
imagine a magnet on a table placed near a fixed solenoid. When the current in the solenoid is activated, the solenoid attracts the magnet performing work due to friction with the table.
how to admit in this case that the magnetic force didn't perform work since apparently there is a force times...
Homework Statement
A particle of mass M=2x10-25 kg, charge Q=8e, and velocity vector v=1.0x105 m/s j enters a uniform magnetic field of strength B=2.5 T. The magnetic firld vector B lies in the x-y plane at an angle of \alpha =70 degrees to the x-axis.
What is the magnitude of this...
Homework Statement
24. A uniform magnetic field is in the positive z direction. A positively charged particle is moving in the positive x direction through the field. The net force on the particle can be made zero by applying an electric field in what direction?
A. Positive y
B. Negative y...
When an object, such as a lump of iron, is accelerated by a magnetic field, where does the extra kinetic energy come from? Does the object become colder, or is it demagnetized?
Homework Statement
In Vermont the dip angle for the Earth's magnetic field(the angle the field lines make with the horizontal) is 74 degree and the component of the field parallel to the Earth's surface is 0.16G. If an electron is shot with a speed 10^6 m/s vertically upward there, how large...
Homework Statement
A "q" charge particle is moving along +y axis with velocity V0 starting from Origin. A friction force is acting on the charge particle " f= -(alpha)V(Vector) ".A constant magnetic field of magnitude B0 acting along +Z axis. The mass of the particle is m. Find the x...
Hi.
My question is how the Lorentz magnetic force F=q\vec{v}\times\vec{B} is derived? Is it due to magnetic moment of charged particles? If the moving charged particle does not have magnetic moment (due to spin, so the torque on the particle is zero) how the magnetic force changes its direction...
Hi
We've just begun studying magnetic force in school. Our teacher told us to explore the possibility of a paradoxical situation as
F=qBv
From different inertial frames, the apparent force will be different, won't it ? Our teacher told us that Einstein's theory of relativity solved the...
Homework Statement
The current in a straight wire is traveling from left to right (in the plane of a page).
Right above the wire is a electron which is moving parallel to the wire and also left to right
The question is which direction is the magnetic force above the wire pointing.
Possible...
QUESTION 1
Homework Statement
Determine the magnetic force acting on an proton (m = 1.67 x 10-27 kg) moving at 2.9 x 106 m/s in a magnetic field of 6.8 T. The proton is moving south. The magnetic field points straight down.
Homework Equations
F = qvBsinø
The Attempt at a Solution...
Homework Statement
It is a multiple choice question. The picture shows two bar magnet attracting each other. A charge is placed in the middle of the distance between the two magnets.
[S-Magnet-N] >>>> (-C) >>>> [S-Magnet-N]
>>> = direction of field lines. (-C) =negative
There is no...
Ok, just a quick question. I'm working through a problem in my physics book and I am asked to find the magnetic force on a current carrying wire that runs along the equator of a sphere. So the wire is not straight, but curves along with the sphere, off the surface of it (not levitating).
My...
Magnetic forces are no-work forces.But when a magnet suspended freely in the Earth's magnetic field(from its center of gravity) rotates to settle itself in an approximately north south direction ,performing some work in the process. Who does this work?Obviously the magnetic forces which are...
Homework Statement
Placed in a cylindrical container of negligible mass, a magnet with weight W is placed on a analytical balance. Another magnet is placed on top of it, hanging in mid-air and is stationary. What is the reading of the analytical balance?
Homework Equations
The...
Hi
The magnetic force applied to electron spin magnetic moment is interpreted by Lorentz force qvXB ? I do not think so. If not, we easily understand why magnetic force can work.
Regards.
Hi all, I ran into a bit of an issue trying to figure out how to properly differentiate the magnetic force due to particle interactions. To be specific, I'm actually looking for the time derivative of acceleration (jerk) due to the magnetic force, but it's essentially the same problem.
For...
Why? Is there an explanation to that?
I know that it's because the magnetic force is perpendicular and so on, but then why the magnetic force works that way?
Thank you
Homework Statement
Question is E=(x,y,z) B=(x,y,z) v=(x,y,z) (in vector form)
For all E,B,v find v(t) and r(t) v and r of course have their vector arrows. Homework Equations
F=ma= qE + qv x B
There is a hint to take second derivatives across and some terms will clear up. I was thinking more...
I am having a problem with my understanding. I could be incorrect, but I think that the magnetic field emitted from a magnet is consistent and doesn't weaken at points further away. Then could someone explain how magnet force weakens with distance. I would also like to know the math so here is a...
Homework Statement
A rectangular loop with length of l = 0.30 m and width w = 0.12 m and a mass of 25-grams falls (from rest) a distance of .28 m before entering a constant magnetic field that points out of the page. The internal resistance of the wire is 5.5 \Omega.
(i) What is the speed of...
Homework Statement
A positively charged particle moves through a region with a uniform electric field pointing into the page and a uniform magnetic field pointing toward the top of the page. The particle can have one of the four velocities shown in the figure ...
Homework Statement
A square 5-turn coil with sides .03 m long and carrying 2 A of current is placed in a uniform magnetic field of .07 T, as shown.
What is the magnitude and direction of the force on each of the four sides?
What is the magnitude and direction of the torque \tau on the...
I know I am not doing collage or uni stuff but this is more advance stuff that that by a little bit.
Does anyone know an equation for the force between 2 magnets. the only one we get is for a magnet and a wire f=ILBsinΘ.
This is to help me with an investigation with an electro magnet and...
Homework Statement
Two parallel loops are parallel, coaxial, and almost in contact, 1.29 mm apart. Each loop is .117 m in radius, the top loop carrying 137 A clockwise, and the bottom look carrying 137 A counter-clockwise. Calculate the force that the bottom loop exerts on the top...
Homework Statement
Decide from the following list of possibilities what is the appropriate direction of the force on the wire for each of the diagrams 1 through 4:
A up
B down
C left
D right
E into the page
F out of the page
G None of these
H No force
Diagram 1
Diagram 2...
How to obtain the magnetic force??
Hi ,
I didn't have any experience to design coil and permenent magnet .
Now i have to do one project using coil and magnet NdFeB. But i haven't got the maximum force. (need maxi force between 1300 to 2500)
I am doing the below procedure. Is it...
an electron m=9.11x10^-31 kg and q= -1.602x10^-19 C enters a region where th magnetic field is constant and perpendicular to the velocity of the electron. the speed of the electron is v=5x10&m/s. the electron moves in a circle of radius 2cm.
a. what is the magnitude B of the magnetic field...
1. Homework Statement :
A wire with a length of 29.0 cm lies along the z-axis and carries a current of 9.00 A in the +z-direction. The magnetic field is uniform and has components Bx = -0.204T, By = -0.968T, and Bz = -0.328 T
Homework Equations
1. Find the x-component of the magnetic...
Homework Statement
An electron that has a velocity with x component 1.7 x 106 m/s and y component 3.9 x 106 m/s moves through a uniform magnetic field with x component 0.029 T and y component -0.15 T. (a) Find the magnitude of the magnetic force on the electron. (b) Repeat your calculation...
When i am shown pictures of bar magnets they show magnetic field lines with arrows diverging out the north pole, and converging back into the south pole
1. Does the magnetic field coming out the north pole, turn back and wind back into the south pole ?
2. what is actually carried along the...
Homework Statement
A long pair of wires conducts 20.2 (amps) od dc current to, and from, an instrument. The wires are 23mm apart, what is the magnetic field 9.7cm from their midpoint in their plane?
Homework Equations
B=(µo/2pi)*(I/d)
The Attempt at a Solution
µo = 4pix10^-7...
Homework Statement
Electricity from the power plant with a power P = 100MW is transmitted by V= 220kV line. At what distance from the wire is the density of the magnetic field equal to the density of the Earth's magnetic field B(earth) = 4 × 10^-5 T? What is the force on the L= 200 m long...
I searched different places but couldn't find how actually you calculate this:-
What is the magnitude of force experienced by a cylindrical piece of iron placed near the end of a solenoid with internal field strength B0.
Figure below shows a length of wire with a central arc, placed in a uniform magnetic field B that points out of the plane of the figure. If the wire carries a current i, what resultant magnetic force F acts on it? Express the answer in terms of B, L, R and i.
I am stuck in this question for...
Homework Statement
What is the magnetic force on a wire 0.25 m long, carrying a current of 4.0 A, when placed in a uniform magnetic field of 0.50 T, at an angle of 45 to the wire?
Homework Equations
The Attempt at a Solution
this question doesn't make sense to me
it said"when...
Homework Statement
A singly charged positive ion has a mass of 2.51 X 10-26 kg. After being accelerated through a potential difference of 264 V, the ion enters a magnetic field of 0.570 T, in a direction perpendicular to the field. Calculate the radius of the path of the ion in the field...
Homework Statement
Sodium ions (Na+) move at 0.844 m/s through a bloodstream in the arm of a person standing near a large magnet. The magnetic field has a strength of 0.259 T and makes an angle of 59.0° with the motion of the sodium ions. The arm contains 95.0 cm^3 of blood with a...
Homework Statement
Each current depicted below by an “x” flows into the screen. At which of the following points (A, B, C, or D) is the magnetic force on a charge the largest?
A_______B_x___C__D_x______
------------1---------2
Note that C is equidistant from both wires...
Someone on YoutTube stated...
Each magnetic pole drops off by 1/R^2. Once you get away from both poles (Cavendish setup) they they start canceling each other out and it ends up as 1/R^3.
Comments?
Here's the link if you need backup info...
Homework Statement
A metal ball having net charge 4.5 × 10−6 C
is thrown out of a window horizontally at a
speed 43 m/s. The window is at a height
63 m above the ground. A uniform horizon-
tal magnetic field of magnitude 0.071 T is
perpendicular to the plane of the ball’s tra-
jectory...
Homework Statement
A rigid wire carrying a current I, consists of a semicircle of radius R and two straight portions of length L. The wire lies in in a plane perpendicular to a uniform magnetic field B. The straight portions are also within the magnetic field. Determine the net force due to B...
http://lh6.ggpht.com/_H4Iz7SmBrbk/SikOL1lh7BI/AAAAAAAABCY/_70wWSK_-Vw/s640/DEVAN.jp
given a square wire frame with a side of length L, placed in a constant extarnal magnetic field B, (B=B*\hat{k}). a current of i flows through the frame anticlockwise(as shown by arrows in diagram)
the...
I'm sorry to post two questions in succession, this is another one on the same topic (I'm obviously having trouble with this whole concept for some reason...)
Homework Statement
Three long parallel wires are 3.8 cm from one another. (Looking along them, they are at three corners of an...
Hi all
I tried to solve one of the magnetostatic problems and I end up with a trivial solution. The problem as shown in the figure, we have an infinite current carrying line and a circle with a radius "b" and current I2. The problem asks for the force being exerted by the line on the...
Homework Statement
If the magnetic field of the wire is 2.5×10^−4 and the electron moves at 1.0×10^7 , what is the magnitude of the force exerted on the electron?
Homework Equations
F=qvBsin(theta)
The Attempt at a Solution
Sin(theta) = sin90 = 1
q = -1
v = 1e7
B = 2.5e-4
So...
Homework Statement
A proton with an initial velocity of magnitude v in the +x direction enters a uniform magnetic field. For which direction or directions of the magnetic field, if any, will there be zero magnetic force on the proton?
+ x
- x
+ y
- y
+ z
- z
Homework Equations
There...
Homework Statement
A particle with a charge of 35.7 uC moves with a speed of 61.1 m/s in the positive x direction. The magnetic field in this region of space has a component of 0.527 T in the positive y direction, and a component of 0.820 T in the positive z direction. What is the magnitude...