Flux Definition and 1000 Threads

Homework Statement Please help me to solve this assignment. [/B] a) A vector field is given by v(x,y,z) = (y, x, z-x). Calculate the flux from this field out of the unit cube, given by x,y,z = [0,1]. b) Use Gauss's theorem to calculate the same flux. Check that you get the same...

If mean seawater temperatures vary from 20C in August to 3C in February, for a patch of water with a depth of 10 meters, what is the net heat flux lost (in W m^-2) to the atmosphere from August to February?

[Q] Find the integral that represents the flux of the vector F = <x^2z, x^z, x^2z> through the surface S given by z = Ax + By + C for 0 <= x <= a and 0 <= y <= a, where A, B, C, and a are positive constants. From what I remember of the Flux. F dot n, where n is a a vector perpendicular to the...

Hey all, I'm having some unique challenges on an optical system I've created, where I'm arraying several LEDs under 1 optic/reflector. We're beginning to see major degradation of the metallic coating that is applied to the part, and I'm tyring to quanitfy the temperature (converted from radiant...

I'm relearning basic electricity concepts and I can't find an answer to a situation I've thought up. Imagine a cube with no enclosed charge and an electric field through it parallel to two of its faces. Guass's law says that the flux should be zero because there is no enclosed charge. Every...

I'm relearning basic electricity concepts and I can't find an answer to a situation I've thought up. Imagine a cube with no enclosed charge and an electric field through it parallel to two of its faces. Guass's law says that the flux should be zero because there is no enclosed charge. Every...

I am reading some papers about astroparticle physics and I see something like Parker limit (monopole). So what is the purpose of setting up this limit ? It is be used to get the expected number of particles per unit area per unit time for later experiments ? Thanks

Hi, I am wondering how i could parameterise the following rectangular cross section of the hollow cylinder in cylindrical co-ordinates. If this surface is better parameterised via a different co-ordinate system then by all means use that system. After I have completed the parameterisation i...

Homework Statement What is the flux of the uniform electric field E=8 N/C through an equilateral triangle with the side a=1m, if the normal vector makes 60 degrees to the direction of the electric field. Homework Equations \phi=EAcosøThe Attempt at a Solution E=8 N/C A= √3/4 m^2 Is the ø in...

So my question is, am I missing any key thing in answering the question below? Question: An electric flux of 149 N.m2/C passes through a flat horizontal surface that has an area of 0.67 m2. The flux is due to a uniform electric field. What is the magnitude of the electric field if the field...

Homework Statement Find the flux through the equilateral triangle with corners at the points (1m,0,0), (0,1m,0), and (0,0,1m) in x,y,z space (measured in meters) for an electric field with magnitude E=6N/C pointing (a) in the z direction, (b) parallel to the line y = x. Homework...

Homework Statement What is the flux of r(vector) though a spherical surface of radius a? Homework Equations to solve this use spherical coordinates. The Attempt at a Solution ∫a . ds

I'm taking E & M II... Would anyone agree that the following statements are true? An electric field changing in time gives rise to a displacement current. A magnetic field changing in time gives rise to an electromotive force.

I have read it in many papers that this is a flux limited sample. But I have trouble in understanding what is the exact meaning of it and why do we use flux limited samples?

Homework Statement What is the flux of r through a spherical surface of radius a? Homework Equations I'm guessing I should use a surface integral? ∫v.da ? The Attempt at a Solution Plugging in: I would get ∫r.da ? but what is a small patch of a sphere? I'm kind of confused...

Each sub-cube of the puzzle has edges 3.0 cm in length. A 8.0 nC point charge lies at the puzzle's center. What is the flux through the one face of the sub-cube labeled with the logo? Note: Its referring to a Rubik's Cube that has 8 sub cubes I used the equation where i divided the charge by...

I'm quite confusing with the theoretical method to estimate photon flux in a media. The method I knew is use the density of photon multiplied by the velocity of photon. Considering the solid angle distribution, for a certain direction only a part of π/4π can be delivery, therefore the...

Dear all, If I have the value of photosynthetic photon flux in unit [ micro mole per meter square per second] as an output for ultra violet sensor. How can I know the corresponding wavelength of that radiation ? and can I know from that wavelength what is the type of the ultraviolet...

Homework Statement Let J=xy^2(\hat{x}+\hat{y}+\hat{z}) A/m^2 denote the electrical current density filed -i.e, current flux per unit area - in a region of space represented in Cartesian coordinates. A current density of J=xy^2(\hat{x}+\hat{y}+\hat{z}) A/m^2 implies the flow of electrical...

...based on the angle. Homework Statement Figure 30-78 shows a wire that has been bent into a circular arc of radius r = 24.0 cm, centered at O. A straight wire OP can be rotated about O and makes sliding contact with the arc at P. Another straight wire OQ completes the conducting...

Homework Statement Hello Guys :) I have been studying neutrinos this term in physics and have been trying to calculate the neutrino flux on earth. I have found an equation but I am just unsure about what the variables in the equation stand for. Homework Equations F = N/(A t) = E/(A...

what is meant by electric flux... and how does an electric flux gets 'cancelled'? can a electric flux exist even when electric field is zero??

The scenario is the following, I am given 2 loops with the same radius, r, a distance of d, and same current of I. In the left loop the current goes counter clockwise, in the right loop the current is clockwise. The two loops centers lie on the same axis which are perpendicular to the plane of...

The scenario is the following, I am given 2 loops with the same radius, r, a distance of d, and same current of I. In the left loop the current goes counter clockwise, in the right loop the current is clockwise. The two loops centers lie on the same axis which are perpendicular to the plane of...

Would anyone have a different explanation and maybe an example of radiation flux? Here is the Wikipedia definition "Radiation flux is a measure of the amount of radiation received by an object from a given source", which is quite clearly explained.

Hi, I have a thought experiment I'd like to share along with a couple of quotes. First, we consider the moment when a body goes from have exactly zero charge to a +Q charge. At that moment, by definition of E field a distance r from point charge q, we have a field propagating from point...

[SIZE="4"]Definition/Summary Flux sometimes means total flow through a surface (a scalar), and sometimes means flow per unit area (a vector). In electromagnetism, flux always means total flow through a surface (a scalar), and is measured in webers (magnetic flux) or volt-metres (electric...

hi, I have been working on equation of state and one of my article says pressure is a momentum flux. what is the physical meaning of this? they have written it as pressure =(1/3) *number density*volume*momentum please explain me the expression regards

Homework Statement Hi, this is not a homework problem per say but I am just struggling with some concepts related to my homework. I am struggling with the concepts of flux linkage and flux cutting. Are these one and the same thing? The following statement in my book is where my confusion has...

Hi, please could someone help with my confusion over these two qauntities. In class we recently learned that magnetic field strength (B) is the number of flux lines (measured in Webers) per square metre. The magnetic flux on the other hand is the total number of flux lines (measured in Webers)...

Homework Statement Here is the prompt: http://imgur.com/FTFz0fZ Homework Equations Magnetic flux = ∫B dot dA Net Flux for closed surface = 0 The Attempt at a Solution For part a: magnetic flux = (7.74 ^i + 4 ^j + 3 ^k)T * (0.254 m)^2 ^i = 7.74 T *...

Hello everybody, I'm studying classical electrodynamics and I'm having a difficulty grasping the concept of EMF. I'll try to explain what causes my confusion. Say I've got a conducting loop, an electrical wire, with some resistance R which contracts (or expands) with time. Let's put that loop...

hello guys :) i need your help with this problem i can understand that in (a) we will use the integral of row(v) * dv to get the charge and in (b) we will use the formule D(r)=Q/[4*PI*r^2] but in (C) should it be zero or what ?? and if it should be zero why in the solution manual it...

Lets consider an ideal transformer in no-load state, i.e. with the primary side connected to a voltage source, and the secondary side in open-circuit. Now, this is what I believe; the voltage Vp in the primary produces a current, which lags the voltage by 90°, as would be in an inductor. This...

I am making a small vertical savonius type wind turbine and would like some general rule guidelines. I am using 14awg magnetic wire--70 turns (2"oval) and ceramic block 1" x 2" x.375" magnets. I am hoping to get the most power possible at lower wind speeds. Is there a rule that states a...

Hi, Could someone please guide me with this question? I'm unsure as to what the curl has to do with finding flux.. PS. This isn't actually assessed work, it's from a past question paper that I am using to revise. Thanks heaps!

Other laws in terms of circulation and flux Why others vector fields no are studied like the magnetic and electric fields? In other words, why others vector fields, like the gravitational and the hydrodynamic, haven't "supreme laws" based in the circulation/flux or curl/divergence?

Axial flux alternator is an easy to make pancake of stationary coils between spinning permanent magnets. Having made one and played with it, i ended up with a few questions. Would it make a good motor? There are axial flux motors for sale, and my alternator spins nicely when hooked up to a...

The interpretation for charge and current through of a circuit is known... "the current is the motion of the charges, electrons, that is repulsed by negative pole and attracted by positive pole through of a conducting wire...". Ok... But what is the explanation for flux linkage and voltage...

Hi. I want to ask a question that does the electric flux passing through a hollow surface depends on the nature of the surface?That is does it depend on the relative permittivity of the surface εr?? Please clear my confusion thanks .

Why change of magnetic flux with the time through a coil induces current in it? Please tell me that what happen to charge in the coil if the magnet or electromagnet wave around this? Also, why a constant magnetic flux does not induces current?

Hello As you know we can find the flux density (B) via vector potential with this equation So with this equation and solution at first i try to find vector potential completely then use above equation Problem: Solution: my approach: now we use curl A to find B we find that but it...

I don't believe they are because the field lines don't have a representation such as flux but I want to be sure. Also are flux lines a vector quantity?

Homework Statement Using the divergence theorem, evaluate the total flux of a magnetic field B(r) across the surface S enclosing a finite, connected volume of space V, and discuss its possible dependence on the presence of an electric field E(r). Homework Equations ∇.B=0 The...

Homework Statement Determine the charge density due to the following electric flux density: \overrightarrow{D} = \hat{r}4rsin(\phi ) + \hat{\phi}2rcos(\phi)+\hat{z}2z^{2}Homework Equations \rho _{v} = \triangledown \cdot \vec{D} \rho _{v} = \frac{\partial }{\partial r} + \frac{\partial...

Homework Statement Find the flux of F=<y,-x,z> through the piece of ρ=2 that lies above z=1 and is oriented up. Homework Equations The Attempt at a Solution S = < x, y, \sqrt{4-x^{2}-y^{2}} > Take Find Sx and Sy, cross them and end up with: dS = <...

I am curious about the effects of oscillation in a heat transfer system. For example consider a simple system consisting of a heat source, a heat sink, and some generic material through which we will flow heat. http://tempneff.com/Hflux.png If we stack them all together, without...

Hello Guys ! iam studing the electric flux and how the relationship between D ( electric flux density ) and E ( elecric field) but i found this problem and i don't know which formula should i use to solve it to find the electric flux i know that Q=(Psi)=the electric flux but i don't...

Homework Statement "A metal bar which runs on 2 long parallel rails are connected to a charged capacitor with capacitance C and a resistor with resistance R. Assume no friction and perfect conductors. The rails are cylindrical of radius R separated by distance d. The bar is a distance x...

suppose a solenoid has N turns What is the Flux through the Solenoid? similarly if a coil has N turns , what is the flux through the whole coil? i know how to find flux through a given AREA,,,like a coil with just 1 turn... How do u find flux for the entire system?