Flux Definition and 1000 Threads

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?

Homework Statement The attached picture shows a spool coil on a iron core with an air gap measuring 2.5mm. The spool is coiled by 0.5mm2 with rho cu = 0.0175 Ωmm2 /m. The average winding diameter for the spool is 3.18cm. Compute the magnetic flux in the spool. Homework Equations...

Homework Statement So this is more conceptual than anything. Say there is a wire loop on the x,y axis and a permanent bar magnet above it on the z axis. I understand according to Faraday's law that as the north end of the bar magnet moves towards the loop the magnetic flux is increasing...

Homework Statement Find the electric flux through the plane surface shown in the figure below if θ = 64.2°, E = 375 N/C, and d = 4.70 cm. The electric field is uniform over the entire area of the surface. Homework Equations The Attempt at a Solution By using the equation:EAcosθ...

Hey! :o I have the following exercise: Apply the divergence theorem to calculate the flux of the vector field $\overrightarrow{F}=(yx-x)\hat{i}+2xyz\hat{j}+y\hat{k}$ at the cube that is bounded by the planes $x= \pm 1, y= \pm 1, z= \pm 1$. I have done the following...Could you tell me if this...

Homework Statement I need to convert from a fv in units of Jy to fλ in units of erg s^-1 cm ^-2 A^-1 fv = 1.0254e-2 Jy Homework Equations fv dv = fλ dλ fλ = fv dv/dλ and because v = c/λ... fλ = fv*c / λ^2 Also 1 Jy = 10^-23 erg cm^-2 s^-1 Hz ^-1 The Attempt at a Solution...

Hello again! :) I am given the following exercise: Find the flux of the vector field $\overrightarrow{F}=zx \hat{i}+ zy \hat{j}+z^2 \hat{k}$ of the surface that consists of the first octant of the sphere $x^2+y^2+z^2=a^2(x,y,z \geq 0).$ That's what I did so far: $\hat{n}=\frac{\nabla{G}}{|...

Hello! :) I am given the following exercise: "Calculate the work and the flux for the path $C: a \cos{\theta}\hat{i}+a \sin{\theta}\hat{j}, 0 \leq \theta \leq \frac{\pi}{2}$ , knowing that $\overrightarrow{F}=x\hat{i}+y\hat{j}$. " To solve this I thought that I could use the Green's...

In my book is says the electric flux density D is equal to εE if the medium is linear and isotropic, where E is the electric field and permittivity ε is a scalar. I have no idea what they mean by a linear and isotropic medium.. How am I suppose to know if the medium is linear or isotropic?

I just have a quick question, and I'm guessing the answer is no but I wanted to make sure that this was sensible. In general whenever we consider flux we think of some kind of closed surface or a scenario where charge closes back on itself. If I were to cut a hole in an infinite plate of...

Homework Statement A particle having charge q = 8.85 μC is placed on the axis of a circular ring of radius R = 30 cm. Distance of the particle from centre of the ring is a = 40 cm. Calculate electrical flux passing through the ring. Homework Equations Flux through a surface = ∫E.ds...

I am confused about when you can use the formula ##\dfrac{q_{enc}}{\epsilon_0} = \Phi## for flux. Is it only when you have a closed surface with point charges? What if you have a closed surface with a non-point charge?

hello If I were to hang a traditional 100W clear glass light bulb from the ceiling, would it radiate 80W (radiant flux), the other 20W lost by air convection/conduction up the wires, or would it radiate closer to 60% or 40% of consumed energy? I can find plenty of figures for the...

In my textbook there are two types of electric flux problems: 1. Find the electric flux through the parabolodial surface due to a uniform electric field of magnitude E_0 in the direction as shown. Here they use ##\pi r^2 * E = \Phi ## 2. An infinitely long line charge having a...

Electric flux textbook discrepancy ?? my textbook says "q enclosed for the Guastian surface in a1 would be the positive charge enclosed by a1: the negative charge does contribute to the electric field at a1 but it is not enclosed by surface a1 and so is not included in q enclosed". ...…..;…...

During my physics lecture, the professor said that flux on a closed surface is equal to zero. What exactly is a closed surface defined as? This problem also requires the use of the Flux = Field * Area formula. In relation to the direction of the electric field, what is the area for Part B...

I have to figure out how to prove that the neutron flux for a point source is given by ø=\frac{S}{4πr^2}. I can get this type of solution, but I have an e^(-r/L) in the numerator. I'm assuming I'm missing some theory somewhere as apparently this is the solution for a point source in an...

Hi! I would like to ask if there is possible to find out the photon flux emitted by a uv source having only the intensity/wavelength spectrum of the source? pp

Homework Statement Evaluate ∫∫r.ndS where r=(x,y,z) and n is a normal unit vector to the surface S, which is a sphere of radius a centred on the origin. 2. The attempt at a solution I decided to use polar coordinates. The radius of the sphere is clearly constant, a. So a surface...

Homework Statement Radioactive decay of elements in the Earth's interior results in a mean heat flux through the Earth's surface of 5x10^-2 W/m^2. What is this flux expressed as a fraction of the energy flux due to thermal re-radiation of absorbed solar energy? If radioactive decay were the...

I'm used to problems which ask me to find the heat flux for when, for example I have a very long cylinder covered with an insulator, each with their respective conductivity coefficient. I'd use the formula \frac{\partial Q} {\partial t} =\int -k\vec{\nabla} T \vec {ds}. But now I have a...

electric flux through a surface placed between... Homework Statement a circle of radius R is kept in the middle of two opposite point charges of Q,-Q.distance between the charges is A, circle is kept at A/2 . what is the electric flux through the circle? Homework Equations ∫E.dA=ø...

Homework Statement A sphere of radius ## R ## carries charge density ## \rho = ar^5 ## where ## a ## is a constant. Find the flux ## \Phi ## of its electric field through a surface of a circle with radius ## R ## if the circle lies in a plane tangent to the sphere and its center touches the...

Homework Statement A square wire frame,in the x-y plane, carrying a current 'I' and with side length 'A' is kept at a distance 'A' from the y-axis . Find the magnetic flux through the other half of the plane(not containing the square loop).Homework Equations The magnetic field due to line...

Homework Statement The Earth's radius is 6370 km . There is a downward-pointing electric field in the atmosphere above the Earth's surface, of average magnitude 140. N/C . a) What is the flux of the electric field out of the Earth? b) What is the charge on the Earth? Homework...

Homework Statement A ferromagnetic core is shown the figure below. The depth of the core is 5 cm. The other dimensions of the core are as shown in the figure. Find the value of the current that will produce a flux of 0.003 Wb. With this current, what is the flux density at the top of the...

Question: Find the outward flux of the vector field F = i-2j-2k across the surface S defined by z = 4-x2-y2 0≤z≤4 At first, I used the Divergence Theorem to solve this problem. I took the divF and got the answer of 0. By definition, integrating 0 three times will still equal 0. Thus, the...

For question 4b in the problem sheet attached below, is my working correct for B outside and inside the coaxial cable? Ans: Outside coaxial:∫B.dl = μI (the integral is between 0 and 2∏r) => B = (μI)/(2∏r) Inside the coaxial: \int_{2\pi a}^{2\pi r} B.dI = μI.\frac{a^2}{\pi...