Flux Definition and 1000 Threads

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...

When using a VFD, am I right in thinking that for an induction motor, torque available at all speeds is constant as the voltage is reduced with frequency to maintain constant flux? Also, am I right in thinking that the mechanical output power of the motor will be less when speed is reduced, as...

Hey, all, so I have been studying this problem all morning, and I do not understand two aspects to this example problem. I included a photo of the diagram used in this problem. You will see two cubes, but the diagram which corresponds to the problem below is the one on the right.PROBLEM: Find...

Here's my work: http://i.imgur.com/9ik31P5.png I need confirmation that the vector fields I found for parts 1) and 2) are correct. I also need to figure out how to find the flux in part 2) when the problem doesn't give any boundaries to evaluate. For part 1), the answer can be found by...

Hey all, I'm working on a project now where I am using a solenoid driven at a 10Hz AC current to create a magnetic field on a solid piece of low carbon iron, and then using a smaller solenoid to capture the magnetic flux coming from the iron. By measuring the phase of the resulting waves...

Magnetic Flux= BA is A the surrounding area affected by the flux or the area of the coil itself that is affected by the flux

In regards to the famous experiment where a magnet is put under a sheet of paper with iron shavings on top, i don't understand why they distribute according to the shape of the magnetic lines of flux. (as seen in the link below)...

I want to know the best tally for MCNP Flux (avg and for each assembly) Please help

Homework Statement Evaluate the flux where F = <(e^z^2,2y+sin(x^2z),4z+(x^2+9y^2)^(1/2)> in the boundary of the region x^2 + y^2 < z < 8-x^2-y^2 Homework Equations The Attempt at a Solution So using the divergence Theorem, ∇ dot F = 6 ∫∫∫6r dzdrdθ where z is bounded...

Homework Statement Let v = -j be the velocity field of a fluid in 3 dimensional space. Computer the flow rate through the T of a triangular region with vertices (1,0,0) (0,1,0) (0,0,1) oriented with upward pointing normal vector Homework Equations The Attempt at a Solution So can...

Hello, I am looking into magnetic flux density in coils can anyone tell me if there is a general equation that equates flux density to the electric current, the coil's dimensions and number of turns? Any help would be appreciated. Thanks.

Homework Statement A charge ##(5\sqrt{2}+2\sqrt{5})## coulomb is placed on the axis of an infinite disc at distance ##a## from the centre of disc. The flux of this charge on the part of the disc having inner and outer radius of ##a## and ##2a## will be A)##\dfrac{3}{2\epsilon_0}##...

Homework Statement Homework Equations The Attempt at a Solution Here are my attempt. The top is when i tried using cylindrical coordinates. Instead of using dA=(cosθ i +sinθj)rdzdθ I used (cosθ i +sinθk)rdydθ since the cylinder is going along the y-axis rather than z. The...

Homework Statement F has a vector potential A = <x,y,x^2+y^2>. Find the flux of F through the upper hemisphere x^2+y^2+z^2=1 z≥0 oriented with upward pointing normal vector The Attempt at a Solution So if F has a vector potential A, would you take the gradient of A to get F? in...

I was reading about different flux shapes, and it depicted the the shape of the fission neutron spectrum to be in the shape of y=e^-x*sinh(sqrt(x)), where y is the spectrum and x is the energy in MeV. note: put that equation into wolfram for easy visualization Then it depicted the slowing down...

hi i have some crazy ideas about tornadoes,lightning and storms emitting magnetic flux loops interacting with the Earth's own magnetic properties and do not have enough electrical schooling to know if it is even a possibility. i was hoping i could get a more learned opinion. the thread is...

If the flux entering such an atmosphere from the core of the star at a radius is r0 is F0, the flux that reaches radius r is given by F(r)=F0*e^k(r^-2-r0^-2) where k is a constant a) Write down a formula for the fraction of the incident flux that escapes from the star entirely...

I know the radiative flux traveling through the atmosphere of a star obeys the equation: dF/dr=-opacity*F*density If we have an isothermal atmosphere the density decreases with radius such that density is proportional to 1/r^2. If the flux entering such an atmosphere from the core of...

Hello People I need help with the following assignment: It states: Consider an ideal moderator with zero absorption cross section, Ʃa = 0, and a diffusion coefficient, D, which has a spherical shape with an extrapolated radius, R. If neutron sources emitting S neutrons/cm3sec are distributed...

i've seen all the super conductors and how it fixes a magnetic field and then levitates, but on which direction does it fixes? for example: if there was a solenoid pointing upwards(the empty middle is vertical) and moving from the axis of -Y to +Y and a ring of super conductor places higher...

Homework Statement Within the spherical shell, 3 < r < 4 m, the electric flux density is given as D = 5(r − 3)3 ar C/m2 a) What is the volume charge density at r = 4? b) How much electric flux leaves the sphere r = 4? Homework Equations ρv=Div D Electric flux = ∫sD.ds=∫vρvdvThe Attempt at a...

I was told it might be better to post this here. Homework Statement The trick to this problem is the E field is in cylindrical coordinates. ##E(\vec{r})=Cs^2\hat{s}## Homework Equations ##\int E \cdot dA## The Attempt at a Solution I tried converting the E field into spherical...

Homework Statement The trick to this problem is the E field is in cylindrical coordinates. ##E(\vec{r})=Cs^2\hat{s}##Homework Equations ##\int E \cdot dA##The Attempt at a Solution I tried converting the E field into spherical coords and I can find the flux that way but it is a complicated...

Homework Statement Given a 60-μC point charge located at origin, find the total electric flux passing through the plane z = 26 cm. Homework Equations The Attempt at a Solution Since electric flux lines from a point charge emanate in every possible direction, only a quarter of...