What is Biot-savart law: Definition and 84 Discussions
In physics, specifically electromagnetism, the Biot–Savart law ( or ) is an equation describing the magnetic field generated by a constant electric current. It relates the magnetic field to the magnitude, direction, length, and proximity of the electric current. The Biot–Savart law is fundamental to magnetostatics, playing a role similar to that of Coulomb's law in electrostatics. When magnetostatics does not apply, the Biot–Savart law should be replaced by Jefimenko's equations. The law is valid in the magnetostatic approximation, and consistent with both Ampère's circuital law and Gauss's law for magnetism. It is named after Jean-Baptiste Biot and Félix Savart, who discovered this relationship in 1820.
I'm fairly confident I can express the strength of a magnetic field along the axis of a current carrying loop at some distance x away using the Biot-Savart Law. I'm just trying to extend this idea for a solenoid with N turns. I'm assuming that the current would become NI in this case?
Regards
Dan
Homework Statement
A square coil of wire of side length 2a lies in the yz plane. A current I flows through the loop. The x-axis is defined such that it passes through the centre of the loop, with the loop boundaries being at z±a and y=±a respectively. Given that I flows in a direction...
Homework Statement
A long (effectively infinite) wire segment
is connected to a quarter of a circular arc with
radius a. The other end of the arc is connected
to another long horizontal wire segment. The
current is flowing from the top coming down
vertically and flows to the right along the...
Dear colleagues,
I have questions regarding Biot-Savart law. From [1], it is shown that the equation (Biot-Savart) is derived from the solution to Poisson's equation (assuming here div A=0)
\begin{equation}
\vec{\nabla}^2 \vec{A} = -\mu \vec{J}
\end{equation}
which is
\begin{equation}...
if you want to calculate the magnetic field of a cylinderical uniform current density
by Biot-savart law,
it will be zero, but by Ampere law it is not zero?
why?
please guide me
Hi, I'm new here but been looking to you guys for solutions for a while now. However, I cannot find the kind of solution on here already, so I thought I'd put it out here.
My main problem with physics is always just finding the formulas I need. If you can at least point me in the right...
I've been looking at my electromagnetism lecture notes I have been given and am trying to make sense of a step made in parameterising a current loop.
I am really confused about the part where dl is first state. I have no idea how the 0, sine and cosine got there. I suspect that it's something...
Homework Statement
Find the B-field at the center of the square loop located above the xy plane, with width (w), and current I rotating counter-clockwise.
Homework Equations
Here is the given equation:
B = [(μo*I*aФ)/(4∏*ρ)](cosα2 – cosα1)
The final answer is for the B-field about...
Homework Statement
A long wire is bent into semicircle of radius R at its center and continues on to infinity in both direcions with the straight segments remaining parallel, as shown in the figure below. Use your knowledge of superposition, Ampere's Law, and the Biot-Savart Law to determine...
Homework Statement
Show that B for a point charge is equal to
Homework Equations
I'm not all that sure. I read that maxwell's equations can be used to derive this, so I'd imagine that it's
The Attempt at a Solution
If it were that, then, if i have a point charge moving...
Homework Statement
A short, straight wire segment of length l carries current I and is oriented so that it makes an angle of 30° with the horizontal. Point P is a distance r below the wire segment.
Which expression below is the best approximation for the magnetic field caused by the wire...
I am reading the Griffiths about finding the curl of B using Biot-Savart Law. I do not understanding the step between equation (5.52) and (5.53) which finding the x components of the following:
(\boldsymbol{J}\cdot\nabla^{\prime})\dfrac{\hat{\xi}}{\xi^{2}}
where...
When finding the angles for the finite length Biot-Savart formula of a filamentary conductor H = I*(cos(α2) - cos(α1))aΦ/(4πρ), is α1 supposed to be calculated at the start of the current, and α2 at the end? I'm just wondering because my book does it this way and vice-versa, so I'm not entirely...
Homework Statement
See attachment for Problem Statement.
Homework Equations
The Attempt at a Solution
Can anyone help me start this problem, or clarify what is being asked? I have no idea where to begin.
This is a simple problem if you work with only magnitude and consider the symmetry of a ring. However, I am taking a detailed approach, and I am not getting the correct answer. Could you please look over my math?
a evenly distributed ring of charge on the positive Y-Z plane has a current, I...
Homework Statement
What is the magnetic induction at a point on a current carrying conductor itself according to biot -savart law? is it zero, infinity?
Homework Equations
The Attempt at a Solution
The Biot-Savart law for calculating magnetic fields due to a current is presented in my freshman physics book as a general way of getting B from I. But there's no time delay implied by the integral. Can I just manually throw the time delay into the integral? For instance, to numerically...
Hi Folks,
I have a quick question about the Biot-Savart Law, I know what it is, but I don't know how to derive it. Could anyone give me either links or show me the derivation with origins. I have tried to google it but to no avail.
Thanks in advance for all your help in advance
Kipper
Homework Statement
Express:
in terms of R, L(t), l, and φ
Homework Equations
Law of Sines and Cosines
The Attempt at a Solution
I have used:
c^2=a^2+b^2-2ab*cosφ which resulted in
r^2=R^2+(L(t)-l)^2-2*R*(L(t)-l)*cosφ
and used the law of sines to get
R*sinφ=r*sinθ...
Homework Statement
A small current element at the origin has a length of 2.0mm and carries a current of 2.0A in the +z direction. Find the magnitude and direction of the magnetic field due to this current element at the point (0,3.0m,4.0m).
Homework Equations
Biot-Savart Law...
Hi,
1. Generally when using Gauss's law to e-field, I'm aware that the the surface you chose must be symmetrical and E-field is constant therefore you would only use Gauss's law for infinite sheets of charge, spherical distribution of charge and infinite line charge am i right?
2. Regarding...
Homework Statement
The Biot-Savart Law states that the direction and magnitude of the magnetic field B
produced at a point P by a current length element I dl is given by:
d\vec{B} = \frac{\mu_0}{4\pi}\frac{Id\vec{l}\times \hat{r}}{r^2}
Where \hat{r} = \frac{\vec{r}}{r}
where r...
Is the Biot Savart law similar to the coulomb law in that it is something that is guessed initially, and later shown to give the same solution that Maxwell's equations give (except Maxwell's equations are a generalisation), or is it something that is proven? And if it is proven, could someone...
An infinite current filament carries a current of 3A and lies along the x-axis. Using Biot-Savart Law, find the magnectic field intensity in cartesian coordinates at a point P(-1,3,2).
dH = I vec{dl} x hat{R} / 4piR^2
let substitude hat{R} with vec{R} / R
then dH = I vec{dl} x vec{R} / 4piR^3...
I'm trying to understand the Biot-Savart law. Isn't the last calculation wrong here: http://planetphysics.org/encyclopedia/QuarterLoopExampleOfBiotSavartLaw.html
I don't understand why "pi" is in the answer.
Homework Statement
Two long straight wires sit at the lower corners of an equilateral triangle and carry current I. Find the magnitude and direction of the B field at the top vertex of the triangle for the case where:
a) the current in both lower wires flows out of the page
b) the...
Homework Statement
I had several questions about the magnetic field vector.
For example when applying the Biot-Savart Law, I was under the impression that each differential element {d{\vec{s}}} containing a current {I} along an infinitely long straight wire exerts a magnetic field...
Homework Statement
"A wire is formed into the shape of two half circles connected by equal-length straight sections. A current I flows in the circuit clockwise as shown. Determine (a) The magnitude and the direction of the magnetic field at the center, C, and (b) the magnetic dipole moment of...
I am curious how you derive this law. It seems that you could derive coulomb ` s law from gauss ` s law, but are there are no similar analogy for Bio-Savart law.
Dear sir/lady
I have a question about the magnrtic force of steady current .
In Biot - Savart law to evalute of B (magnetic Field ) , below the Integral we have to do a cross product Idl'*(r-r')/|r-r'|^3 that r and r' are the vector position of the field and source . How we can evaluate this...
I read that the Biot-Savart Law is analogous to Coulomb's Law, but for Magnetism instead of Electricity. Back when we learned about Coulomb's Law, I remember my professor saying that Coulomb's Law cannot be explained and that there is no mathematical proof for why Coulomb's Law exists. Is this...
Suppose an electron orbits a proton at a distance of 'r' with speed 'v'.
How could i determine the magnitude of the magnetic field at the location of the proton?
I thought it would make sense to use The Biot-Savart Law, but i don't know where to begin:
dB = \frac{\mu_o}{4\pi} \frac{I ds x...
Two very long, straight, parallel wires carry currents that are directed perpendicular to the page, as in the figure below. Wire 1 carries a current I1 into the page (in the -z direction) and passes through the x-axis at x=+a. Wire 2 passes through the x-axis at x=-2a and carries an unknown...