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.
Noob, apologies to all.
What is magnetic force? I can calculate it, and know that it is perpendicular to the motion of an electric force, but what is it? Just because I can calculate it does not mean that I know what I am calculating.
Thanks
A rectangular loop of wire measures 1.0 m by 1.0 cm. If a 7.0-A current flows through the wire, what is the magnitude of the magnetic force on the centermost 1.0-cm segment of the 1.0-m side of the loop?
Fm = ILBsin of angle
Fm = Magnetic force
I= Electric current
L= Length of...
Homework Statement
As shown in the attached figure, two rails of conducting wire,M and N, run parallel to each other on a horizontal plane and are separated by distance l. The rails are in a magnetic field of magnetic flux density B that is in the vertically upward direction. An electrically...
So, I have an apparent paradox:
Consider a particle moving with constant velocity, v, along the x-axis.
It now enters a constant magnetic field with is parallel to the y-axis. So there is a force, F=q(vxB) which acts on it, and points in the positive z-direction at first, but then as the...
Homework Statement
The problem is in the attached image.
Homework Equations
The Attempt at a Solution
I used the third left hand rule (seen in one of the attached images) and pointed my thumb (direction of the current) downwards because the question states that the current flows...
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A while back I raised the similar question regarding absolute nature of Magnetic force due to a current carrying wire on a moving charge. But supposedly I was shown to be incorrect.
Since, Magnetic filed is a relativistic effect, then every magnetic force should be...
Homework Statement
question - see image
Homework Equations
The Attempt at a Solution
so I use the equation F = BIl
F = 0.2 * 0.4 * 8 = 0.64
Surely I just divide it by the number of electrons (8*1028) to get the answer
BUT this does not give the correct answer.
The correct answer is D?
A charged particle is placed next to a current-carrying wire. The wire produces a magnetic field, but if the particle is at rest, the field exerts no force on it. However, in a different inertial reference frame moving at speed v parallel to the wire, the particle is seen to be in motion, and so...
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I have a few questions that I cannot find answer for in my physics book or online.
1) Why does moving a charge parallel to the magnetic field result in zero magnetic force?
Is this quality...
Magnetic Force on Various Sides of Spinning Loop??
Homework Statement
A horizontal uniform magnetic field of magnitude 0.4 T is oriented at an angle of = 65° relative to a line perpendicular to plane of a vertical, rectangular loop, as indicated in the figure. The loop has a height of 8 cm...
I have a homework question that I am having some trouble with. This is my first post - so be easy on me.
Question:
A weight-lifter is able to hold a barbell with a maximum total mass of 205 kg above his head. A physicist uses him to conduct a classroom demonstration, asking him to hold one...
Homework Statement
At a particular instant, charge q_1 = 4.80×10^−6 C is at the point (0, 0.250m , 0) and has velocity v_1=(9.2*10^5 m/s) i_hat. Charge q_2 = −2.50×10^−6 C is at the point (0.150m , 0, 0) and has velocity v_2 = (-5.3x10^5 m/s) j_hat.
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Homework Statement
A particle moves through a magnetic field. In which situation is the magnetic force nonzero?
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Homework Statement
The current in a wire consists of n electrons per unit volume moving with a velocity v. What is the effect on these electrons of the magnetic field set up by the current itself within the wire? What is the force on one electron at a distance r from the centre of the wire...
Homework Statement
The problem is shown in the link below:
http://postimage.org/image/do2b7xz0b/
Homework Equations
Biot-Savart Law's and dF=Idl x B
The Attempt at a Solution
My attempt is really just a mess. I essentially want to break it up into 2 segments. (1) Being the...
Homework Statement
Find the magnitude and direction of the magnetic force on a charged particle with charge -4nC and velocity
\vec{v} = (2.5\times 10^{4}) \hat{i} + (1.1 \times 10^{4}) \hat{j} (m/s)
if the magnetic field in the region is given by
\vec{B} = (1.2\times...
hello, I was just thinking since a photon trajectory is affected by a magnetic force.then I would like to know how much force does it take to do just so.
Homework Statement
r= 0.12m
B = 0.0720T
I = 21.0A
Fm= 0.104 N [up]
A magnetic force of 0.104 N [up] acts on a 12.0cm long wire that runs[N 10 degrees E] through a magnetic field of 0.0720 T. If the current in the wire is 21.0 A, then what is the direction of the magnetic field?
This...
Here is the question:
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Homework Statement
Figure is attached.
A thin copper bar of length = 14.0 cm is supported horizontally by two (nonmagnetic) contacts. The bar carries current I1 = 105 A in the -x direction, as shown in the figure below. At a distance h = 0.500 cm below one end of the bar, a long straight...
Homework Statement
A u-tube of uniform square cross section has electrodes sealed inside the upper and lower walls of the horizontal section. The two arms of tube being vertical. The tube is partially filled with liquid sodium and a direct current is passed between the electrodes. A uniform...
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a) 2.66 N
b) 3.86
c) 5.60 N
d) 8.12 N
e) 11.8...
Hello. So: Why does magnetic force tend to increase magnetic energy?
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I have some very basic question that I've been struggling to find the answer to and before I go and buy some magnets to do some test of my own I thought I'd ask here:
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Homework Statement
Imagine you have a magnet (Henceforth named MagX) which weighs .03lbs, and it is being continuously pushed by another magnet's polar likes (Henceforth named MagY) with a force of 3 PSI. Is it possible to find the peak velocity of MagX, assuming that MagY stays at a constant...
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Sorry for slightly disregarding the proper format but I'm really quite lost so I can abide by what is expected. However I will be detailed
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F== B*M* ...
is anybody here can help me ?
Homework Statement
a closed wire loop with current I is in a uniform magnetic field B
show that the total magnetic force on the loop is zero
Homework Equations
The Attempt at a Solution
everywhere that I've looked just states it without explaining why
according too: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/wirfor.html#c1F=(u * I *I2)/(2pi *r )
i thought it would be inverse proportional to the square of the distance?! can this be right?
Magnetic force between two parallel hanging wires (solved)
Homework Statement
Two long, parallel wires hang by 4.00-cm-long cords from a common axis. The wires have a mass per unit length of 1.30×10−2 kg/m and carry the same current in opposite directions. What is the current in each wire...
A 1.0 kg copper rod rests on two horizontal rails 1.0 m apart and carries a current of 50 A from one rail to the other. The coefficient of static friction between rod and rails is 0.60. What are the (a) Magnitude and
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The figure shows a current i through a wire in a uniform magnetic field , as well as the magnetic force acting on the wire. The field is oriented so that the force is maximum. In what direction is the field?
I have uploaded the figure, and the relevant equations.
My reasoning:
-L is in...
Homework Statement
1. There is a counterclockwise current I in a circular loop of wire situated in an external magnetic field directed out of the page as shown above. The effect of the forces that act on this current is to make the loop
(A) expand in size (B) contract in size...
Homework Statement
http://img710.imageshack.us/img710/9295/roachj.th.png
Uploaded with ImageShack.us
http://img146.imageshack.us/img146/6360/61565460.th.png
Uploaded with ImageShack.usThe Attempt at a Solution
The vertical conductors does nothing because their forces are only horizontal...
Homework Statement
A strong magnet is placed under a horizontal conducting ring of radius r that carries current I as shown in the figure below. The magnetic field makes an angle θ with the vertical at the ring's location.
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I have the problem that I want to calculate the force of a magnet acting on a ferrofluid. I know this is is difficult but I am trying to make some simulations of physical behavior on ferrofluids
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Homework Statement
A high-voltage power lines carries a current of 110 A at a location where the Earth's magnetic field has a magnitude of .59 G and points to the north, 72 degrees below the horizontal. Find the direction and magnitude of the magnetic force exerted on a 250-m length of wire...
Homework Statement
1) A charge Q is placed in a uniform magnetic field of magnitude a that proceeds in the -z direction. Its displacement is given by r(t) = (at^2+bt, 2bt, a).
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Homework Statement
See figure attached
Homework Equations
The Attempt at a Solution
I've attempted to draw the magnetic fields resulting at the location of wire 4 due to wires 1, 2, 3.
I denoted them as B4,1, as in the "The magnetic field at 4 as a result of 1".
Are these...