Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. A flux is a concept in applied mathematics and vector calculus which has many applications to physics. For transport phenomena, flux is a vector quantity, describing the magnitude and direction of the flow of a substance or property. In vector calculus flux is a scalar quantity, defined as the surface integral of the perpendicular component of a vector field over a surface.
Hi,
I was reading my astrophysics textbook and came across solid angles. I'm not sure I fully understand, for example there was a problem in the book that went as follows.
The attached "math.jpg" shows a light source (yellow) in the centre of an arc. The problem is 2D, but the arc is...
I've recently accepted a short-term contract position as basically an electronics technician / solder monkey and we're using rosin-core silver/tin/copper solder for our boards for RoHS compliance. Up to this point, I've only done low-volume production where it's been more or less acceptable to...
Please Help! Integration!
Hi!
I'm having a little problem with an exercise and I don't know how to sort it out.
Basically what I have is a tube of 5mm ejecting spray fuels. At the exit plane I have positioned lasers to measure the volume flux at different locations, starting from one side...
Homework Statement
Charge of uniform surface density (4.0 nC/m2) is distributed on a spherical surface (radius = 2.0 cm). What is the total electric flux through a concentric spherical surface with a radius of 4 cm?
Homework Equations
\Phi = E 4 \pi r^2 = \frac{q}{\epsilon_0}...
Does anyone have any clue on how Gauss experimented on his law for magnetism?
The experiment he did to find the magnetic flux
Any help will be appreciated
Homework Statement
The first question I used BA cos(delta)
My answer was 0.512 Weber
The second question I used NBA
My answer was 9 Weber
I would like to know whether my answers are right thank you
[PLAIN]http://img263.imageshack.us/img263/751/doentx.jpg
I've been reading up on tesla's wireless power transmission lately, and I've been wondering how magnetic flux through the center of a toroid induces a voltage in its coils. From what I understand, the time derivative of magnetic flux through a loop is proportional to the induced voltage...
Homework Statement
A stationary loop of wire is placed in a magnetic field directed into the page. The current in the loop of wire:
and then it lists 4 multiple choice options. the answer is: the current in the loop of wire is clockwise if the magnetic field is decreasing.
Homework...
Consider the following system - A coil is wrapped around a soft iron core as shown below. A permanent magnet is placed at one end of the coil.
+--+-----+--+
| | | |
Coil +ve Side --> | | | | --> Coil -ve Side...
Homework Statement
A vertical electric field of magnitude 2 X 10^4 N/C exists above the Earth's surface on a day when a thunderstorm is brewing. A car with a rectangular size of 3.00 m by 1.50 m is traveling along a dry gravel roadway sloping downward at 7.0°. Determine the electric flux...
Lets us say I have a cube and I apply to a face of the cube a heat flux of 100 watt/m^2.
Lets us say i divide the face of the cube into say 10 elements (area of each face of the element is 1 m^2).
What will be the flux on each element , will it also be 100 watt/m^2?
Sorry for a...
Homework Statement
Calculate the value of magnetic flux density in air in the middle of two straight parallel wires carrying currents of 10A and 20A in the opposite directions. The distance between wires is 10cm.
The Attempt at a Solution
\oint \vec{B}\cdot d\vec{A} = \Phi
\oint \frac{\mu_0...
This isn't homework. I've been restudying vector calculus from the beginning to end on my free time and got stuck on this problem. I am not sure what I'm doing wrong, but it may be a calculation error since it has so much calculation involved.
Homework Statement
Evaluate the surface integral...
Problem
A long non conducting solid cylinder of radius R has a non-uniform change density rho or (p) that is a function of the radical distance r from the axis of the cylinder. given by rho or p(r)=Ar^2 Find the E-field at regions r<R and r>R?
I'm trying to figure out the sensitivity of the Fermi LAT, in units of spectral flux---e.g. Jansky, or a limiting magnitude which could easily be converted. I've only found sensitivity in traditional high-energy terms, e.g:
4\times10^{-6} \textrm{ photons/s/cm}^2
for photons above 100 MeV, with...
For my own edification.
The Planck Function when integrated over all wavelengths will give the radiated power per unit area for a black body. Would I be right in thinking, that if I had a known temperature for the black body source or indeed a kT value for that source that by using the...
I'm translating the problem, so sorry for the errors.
Homework Statement
Radius of the upper circumference = 5cm
Radius of the lower circumference = 9cm
Resistance/meter = 3.00 ohm/meter
B is the magnetic field: DB/dt = 2.00 T/s
What's the magnitude of the current, and where does the...
How can we calculate the flux in a coil which carries a current? I am having trouble determining the field at any point inside the coil other than the center? Any help is appreciated...
According to Faraday's laws... change in magnetic flux linking a coil induces current in the coil.., but for conduction of electrons ...there must be an electric field ! how is the electric field induced in the coil??
The best understanding I have got is that it is the word we use to describe flux - a fundamental state of the universe.
Maybe the question can be rephrased as 'why do things affect each other?'
Homework Statement
What is the temperature of a star if the flux at 450 nm is measured to be 1.3 times the flux at 650 nm.
Homework Equations
I tried to use the equation Flux = 2πhv3/c2...
Four resistors (1kohm) in series form a closed circuit. The total magnetic flux linking the circuit increases at a rate of 0.5 Wb/s in the direction pointing out of the paper. Find the direction and magnitude of the induced current in the circuit
emf=-d(magnetic flux)/dt
I'm having...
Homework Statement
Use the Divergence (Gauss's Theorem) to find the outward oriented closed surface (no boundary) for which the flux of F(x,y,z) = (16x-xz^2)i-(y^3)j-(zx^2)k is maximized.
Homework Equations
Gauss's Theorem
The Attempt at a Solution
divF = 16-z^2-3y^2-x^2 > 0 I think ?
Given a black hole metric g_{\mu\nu} and gauge field A_\mu, how do I find the flux through a sphere of a black hole.
In simpler terms how do you find \star F (the hodge star, I believe) using the metric ??
Does the gravitational flux has the form (4*(pi)*G)*m through a closed surface?
The reason i feel feel this is because there is a parallelism between gravitation and electrostatics. The electrostatic force has the same expression as gravitational force and even the two shell theorems are valid...
Homework Statement
A current carrying loop of wire is being monitored using a Hall-effect magnetic field probe placed at its centre. The loop is in air and has a radius of 0.5 m. It is required to monitor the magnetic flux in order to trip the circuit breaker if the current exceeds 100 A...
Homework Statement
A 400 turn coil wound over a length of 30mm has a core GO steel and has a current of 500mA
flowing through it. Find the density of the flux produced.
Homework Equations
N=400, I=0.05, l=0.03 F= IN ; Φ=F/Rm ; B=Φ/A ; Rm=
The Attempt at a Solution
F=20 At
How do I find the d{flux}/dtime in the faradays law? The problem I'm facing i need to flux which depends on B and area. I have a coil of wire which is about 6 inches away from the center which hold a permanent magnet. How do I find the B [flux density] in the coil wire and how do find the flux...
Homework Statement
Let S be the surface z=x+y, 0≤x≤1, 0≤y≤1. Find the upward flux of the vector field F =<z,x,y > across S.
Homework Equations
∫∫SFndS
The Attempt at a Solution
parametrize:
x=x
y=y
z=x+y
rx=<1,0,1> ry=<0,1,1>
Homework Statement
Flux integral:
S is the portion of the cylinder with these cylindrical coordinates:
0<=z<=3 r=1 0<=theta<=pi/2
orient S with outward normal vectors from z-axis and compute the flux of F = <2x,y,-3z> across S
Homework Equations
Flux integral ∫∫SFdS = ∫∫S F...
If F is a well defined vector field and divF=0 then does that mean the flux of F across any surface in 3D would also be 0?
I know that in divergence theorem, divF=0 automatically implies that the integral will be 0 but what about across flat surfaces and planes?
Homework Statement
<\body>
<with|mode|math|\<b-phi\><rsub|B> = <big|oint>><with|mode|math|\<b-B\>
\<cdot\> \<b-d\>\<b-A\>>\
\;
magnetic flux is proportional to the number of field lines passing though
the surface
\;
</body>
<\initial>
<\collection>...
The Problem: I have a paraboloid open along the positive z-axis, starting at the origin and ending at z = 100. At z=100, the horizontal surface is a circle with a radius of 20. Water is flowing through the paraboloid with the velocity F = 2xzi - (1100 + xe^-x^2)j + z(1100 - z)k. I'm asked to...
Hi,
I would like to verify analytically that a vector potential of the form A=1/2(-yB0,xB0,0) produces a constant magnetic flux density of magnitude B0 in the z direction.
(I guess I'd have to use the relation B=\forall\wedgeA...)
Hi,
I'm new to the entire neutronics field. I've learned about adjoints as a physics student in undergrad and I'm doing nuclear engineering for my graduate studies. I understand how to derive the adjoint operator for the diffusion equation, but I'm a bit confused as to how to calculate the...
Homework Statement
The directions for this calculus problem say find the flux of F across surface S (that is find the double integral F (ds)) where F = (x,2y,z), S is the part of the cone (x^2+z^2)^1/2=y inside of the cylinder x^2+z^2=1 and n points to the right.
Homework Equations...
Hi,
Im asked to evaluate the flux through a surface s2.
The overall region R is a half ball bounded by disc s1 with y=0 and x^{2}+z^{2}=4 and the hemispherical shell s2 with y>=0 and x^{2}+z^{2}+y^{2}=4.
In the region there exists a force with field F = -zi+y^{2}j+xk.
I have tried...
Homework Statement
if i have a sphere just above the z=0 plane, may i know what is the inward flux for the bottom hemisphere?
namely, is it +ve or -ve? my answer says its +ve, but why? i thought the +ve flux is always pointing outwards? so shouldn't the inward flux at the bottom of the...
a disc of radius r we have to find electric flux at a point which is at a distance r from the centre
i have used e=(sigma/2eo)(1-x/sqrt(r^2+x^2)) the area da=2pir*dr
i know flux=closed integral (e.da)
and x=r
after that what should i do
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Homework Statement
A metal sphere of radius a is surrounded by a metal shell of inner radius b and outer radius R, as shown in the diagram below. The flux through a spherical Gaussian surface located between a and b is 1.20Q/εo and the flux through a spherical Gaussian surface just outside R...
Homework Statement
I understand that if we have a solenoid with AC current running through it, it will create a changing magnetic flux.
Suppose now we place the solenoid in the centre of the a single loop wire, according to faraday's law of induction, that single loop wire will have a...
Let W be the solid bounded by the paraboloid x = y^2 + z^2 and the plane x = 16. Let = 3xi + yj + zk
a. Let S1 be the paraboloid surface oriented in the negative x direction. Find the flux of the vector field through the surface S1.
b. Let S be the closed boundary of W. Use the Divergence...
Homework Statement
Compute the flux of the vector field, , through the surface, S.
\vec{F}= 3xi + yj + zk and S is the part of the surface z + 4x + 2y = 12 in the first octant oriented upward.
Homework Equations
by definition from my book the integral is
\intF(x,y,f(x,y)\circ<-fx,fy,1>dxdy...
Homework Statement
A wire of resistance 11 ohms and length 2.3 m is bent into a circle and is concentric with a solenoid in which the magnetic flux changes from 8 T·m2 to 6 T·m2 in 0.2 seconds.
a) What is the emf in the wire?
b) What is the non-Coulomb electric field in the wire?
c)...
Homework Statement
A circular conducting coil with N=100 turns and radius "r" is oriented in the xy plane. The leads of the coil are connected to a circuit with resistance "R." A time varying external magnetic flux density "B" is applied along the z-axis.
What is the total magnetic flux...
Homework Statement
The electric field is measured all over the surface of a cylinder whose diameter is 8 cm and whose height is 20 cm, as shown in the diagram. At every location on the surface the electric field points in the same direction (+y). E1 is found to be 533V/m; E2 is 730V/m; E3 is...
Say I have a closed metal rectangular shaped wire in a region with a magnetic field.
If the magnetic flux is constant, there is no induced current, no experienced force, and no EMF?
If I start the changing the magnetic flux, I suppose by increasing the magnetic field, there will be an...