Flux Definition and 1000 Threads

Can anyone tell me the physical interpretation of the flux of an electric field through a closed surface. I think I do understand what flux is: Like in a water pipe a flux integral over the surface of the pipe would be the volume of water passing through the surface per second. What is the...

24. A square coil is perpendicular to a uniform magnetic field. Which one of the following would increase the magnetic flux through the coil? A. Decreasing the area of the coil. B. Increasing the number of loops in the coil. C. Removing the coil from the magnetic field. D. Increasing the...

Homework Statement A charge q sits in the back corner of a cube, as shown in the attachment. What is the flux of E through the shaded side? Homework Equations The Attempt at a Solution I know that I need the surface integral of E over the shaded area, but the problem is with...

Can I alter the quanta of magnetic flux using length contraction of the source creating the B field. Like for example could I get half of the flux by moving relative to the B field. Or some other fraction of it. The unit of flux is like \frac{h}{2e}

Homework Statement Two bars, each 30cm long, and each having a resistance of 2-ohms, are connected to a 1,500 volt battery. The bars are attached to each other with 3 insulating springs, each having a spring constant of 9N/m. The two bars are initially at rest, 4cm apart. The switch is...

If I have two spheres of the same radius, they can still have different temperatures. However: What if the colder sphere is closer to the ideal of being a blackbody than the hotter sphere? http://en.wikipedia.org/wiki/Emissivity In an open system without internal energy generation, both...

Homework Statement During the design of a new doppler radar unit, you have two circular plates with radius R = 3 cm and a plate separation of d = 5 mm. The magnitude of the electric field between the plates is given as: E = (700 V/(m sec2))*(1-r/Rp)*t 2 where Rp is the radius of the plates...

Homework Statement When is the magnetic flux on a section of a closed surface equal to zero? A. When the magnetic field is in the direction opposite that of the section’s area vector. B. When the magnetic field is in the direction of the section’s area vector. C. When the magnetic field...

Homework Statement Which describes the magnetic flux through a section of a loop? A. It is a vector that is directed outward through the section. B. It is a vector that is directed inward through the section. C It is a vector that is tangent to the section. D. It is a scalar...

Homework Statement A 2 \mug sample of {}^{47}Ca is encased in a lead sphere. What is the photon intensity 5 cm from the source? Use some of the tables in your book to find the required information. Homework Equations Flux/Intensity of photons from a point source...

Does a magnetic flux tube always have a current flowing in it? Where is the current? Electrons on the surface and protons inside? Why are flux tubes magnetically buoyant? That is, why is there a difference in pressure inside and outside the tube. As far as these questions go, is...

A 30mH solenoid inductor is wound on a form 0.4 m in length and 0.1 m in diameter. A coil is tightly wound around the solenoid at its center. the coil resistance is 5.0 ohms. The mutual inductance of the coil and solenoid is 60μH. At a given instant, the current in the solenoid is 0.3A and is...

Would a voltage amplification with the same power output increase plasma density and increase the magnetic field of the plasma, if the power output does not change? In the case of a USB plasma globe with a current flow of 300mA through 5 volt, amounts to 1,5W. CASE A: Ofcourse this...

This question about the variation of the aforementioned quantities in a transformer. Now according to me and my knowledge of electricity this is how I feel it should play out : If the input current were a sine curve that varies with time then : Input voltage = cosine curve i.e. it is...

Can the TdS by a system be calculated by taking the area, time double integral of the heat flux density? If so, is it possible that this double-integral would take on an opposite sign if inside there was a dominating, growing black hole, where, I would presume, heat flows inwards, and not...

Homework Statement A wire circle of radius 0.050 m is embedded in a solenoid of length 0.20 m with 1000 turns that carries a current of 0.50 A. If a vector that is normal to the plane of the circle makes a 40° angle with the axis of the solenoid, what is the magnetic flux through the loop...

Homework Statement A circular coil has 25 turns and a radius of 5 cm. It is at the equator, where the earth’s magnetic field is 0.7G north. Find the magnetic flux through the coil when its plane is (a) horizontal, (b) vertical with its axis pointing north, (c) vertical with its axis pointing...

May I know that are there any different between the electromagnetic flux and magnetic flux? Are there any electromagnetic flux in a permanent magnet machine? What kind of flux will go through the permanent magnet machine's stator cores with copper wires on it? I am really sorry to ask so many...

Homework Statement "A solenoid is wound with 400 turns on a form 4cm in diameter and 50 cm long. The windings carry a current that produces a magnetic field, of magnitude 1.5mT, at the center of the solenoid. The magnetic flux through the solenoid is closest to? Homework Equations...

Hi, we have been doing lots of work recently on magnets. we have learned about the ideas of flux, and using them to describe induction and how transformers work etc. i feel that i understand quite well about these ideas, but now i have come across this idea of 'flux linkage'. i do not...

Ok, Please correct me if I'm wrong; Flux lines are a sort of mathematical visualisation of magnetic fields, they do not exist. As such, there still exists a magnetic field between flux lines (?), just in calculations we use flux lines because they are simpler (?). In voltage transformers...

In solving a flux integral over a flat surface, inclined above the xy-plane, does the boundary of the surface influence the flux only through the integral limits? (and not through its normal vector) Let's say that there is an elliptic surface inclined above the xy-plane. The orientation is...

Homework Statement A cone is resting on a tabletop as shown in the figure with its face horizontal. A uniform electric field of magnitude 4550 N/C points vertically upward. How much electric flux passes through the sloping side surface area of the cone? Homework Equations flux = ∫...

A charge q is kept at the centre O of cube of length L(ABCDEF). Another charge q is kept at a distacne L from the centre O. Find the flux through face ABCD Well the flux through whole of the cube will remain unchanged that is q/ε. But now since we have another charge q outisde the cube we...

Homework Statement assuming that friction is negligible and tthat electromagnetic forces are constant, (when they occur) calculate the speed of the cart at point 5w this is part IV of a question, so in the other parts and in the given, i found out that: mass of the cart=0.5kg number of...

Let F=(7z+8)i+2zj+(2z+7)k, and let the point P=(abc), where a, b and c are constants. In this problem we will calculate div F in two different ways, first by using the geometric definition and second by using partial derivatives. (a) Consider a (three-dimensional) box with four of its corners...

Homework Statement Homework Equations afaik, flux in inductor = Li. at t=0, current through L is 0. so change of flux = LΔi = L(i-0)=Li The Attempt at a Solution at t=∞, i through cap. is 0. so, i get the following equations: 5(i1+i2)=20 5(i1+i2)+ 5i2=10 i get...

Homework Statement Consider the surface S with the graph z = 1-x^{2}-y^{2} with z≥0, and also the unit disc in the xy plane. Give this surface an outer normal. Compute: \int\int_{S}\vec{F}\bulletd\vec{S} where \vec{F}(x,y,z) = (2x,2y,z)Homework Equations \int\int_{S}\vec{F}\bulletd\vec{S} =...

Dear Forum Users, I am looking for a database of proton fluxes. I have found already the SOHO database: http://umtof.umd.edu/pm/ but I need also the database for energy range of 1keV to 100 keV range. Does someone could send me some hints where to search? nykon

Hey everyone, First I'd like to say my thanks to the community for all the information I managed to glean while lurking on the forum and doing my schoolwork over the last year or so. It's been an invaluable resource to me! Now, on to my question. (I see that it says not to post homework...

Dear PFs I am facing a problem with finding a good Hall-effect magnetic flux sensor which should be fixed in the top of a probe working in a very intense magnetic field. The probe must be aligned to a certain degree with respect to the direction of the main field. The requested alignement...

Dear forum users, I have a quite simple question. I have got a flux of protons measured in 1/(cm^2 s sr), I would like to have it in 1/(cm^2 s). nykon

http://imgur.com/VsDrQ,dJ2iv#1 So according to the picture, I found the transformer voltage equation and current equation to be the following: Precondition: i1 is current in left loop i2 is current in 2nd loop Transformer Voltage Eq: V1/N1 = 4i2/N2 Current Eq: Ni(i1) =...

Homework Statement A sphere of radius R is placed in a uniform electric field of E=233 N/C i. Find the electric flux into and out of the sphere. Homework Equations I understand that Gauss's Law is shown as... ∫E dot dA = Q/epsilon not The Attempt at a Solution Well, since...

I'm learning the basics about electromagnetism, including that a changing electric flux through an open surface causes a magnetic field. Obviously a capacitor causes this, but doesn't a resistor like a light bulb (whose resistance varies with temperature and therefore time) also cause this?

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 To determine monochromatic flux I use: 2πhv3/c2 ex-1 x= hv/kT The Attempt at a Solution So basically I plug in the...

Homework Statement Let's say the sphere has a radius of 3 and is centred at (3, 0, 3). Is there a way to implement spherical cooridnates, or is it essentially impossible for this situation to not get messy? I have searched everywhere as to how I can evaluate this, but to no avail. Any help is...

Homework Statement The faintest stars a naked eye can see under the ideal conditions are of m = 6 magnitude. Diameter of a maximally dilated pupil is d = 9mm. Calculate the magnitude of the faintest star a person can see if observing through binoculars (d = 5cm), a large backyard...

A point charge 6.50 nC is at the center of a cube with sides of length 0.260 m. PART A: What is the electric flux through the surface of the cube? PART B: What is the electric flux through one of the six faces of the cube? ATTEMPT: A) Total flux enclosed by the cube = Q / eo...

A tetrahedron has an equilateral triangle base with 20-cm-long edges and three equilateral triangle sides. The base is parallel to the ground and a vertical uniform electric field of strength 200 N/C passes upward through the object. (a) What is the electric flux through the base? (b) What is...

Homework Statement An infinite line of charge with charge density λ1 = 2.9 μC/cm is aligned with the y-axis as shown. a = 7.9 cm. h = 8.8 cm. λ2 = -8.7 μC/cm. Another infinite line of charge with charge density λ2 = -8.7 μC/cm parallel to the y-axis is now added at x = 3.95 cm as shown...

Homework Statement Find the flux of \vec{F}=(x, y, z) outward across the sphere x^2+y^2+z^2=a^2. I am able to get it to this point: \int\int_Cadxdy and I then convert it to polar coordinates, and integrate rdr from 0 to a, and theta from zero to 2pi. However, this does not give me the...

I have a question about electricity and magnetism. My teacher went through these chapters in 3 days, and I am completely confused. Can some body please explain what exactly is flux, capacitance, difference potential, and voltage? And can you also explain to my what the number stands for when...

A point charge Q at the center of a sphere of radius R produces an electric flux of (flux symbol) coming out of the sphere. If the charge remains the same but the radius of the sphere is doubled, the electric flux coming out of it will be? LINK TO ORIGINAL PROBLEM: http://i.imgur.com/e8Tmt.png...

Homework Statement Probably a silly question, but I can't figure it out. Why is magnetic flux defined as magnetic field strength per unit area if it is found by multiplying the strength of magnetic field B by area A rather than dividing by area A? Thanks for any responses :)

Does relativistic aberration apply to electric fields and magnetic fields? If a spaceship accelerated to a relativistic speed with respect to an initial inertial frame, in a constant direction with respect to a uniform electric field, do the effects of aberration affect the magnitude of electric...

Homework Statement http://s1.ipicture.ru/uploads/20120121/YUmpPl4N.jpg The attempt at a solution First of all, taking a look at the wording in the problem itself. I am not sure if the unit normal vector is supposed to be outward or inward. There is the "outward flux" but the "inside the...

Hey everyone. Having a bit of trouble with a 4-part question. So I thought I'd post here, if someone could check the first 3 parts and perhaps help me with the last part, I'd really appreciate any feedback! Thank you so much! :) Homework Statement a) A circular loop is held to the left of a...

Homework Statement http://s1.ipicture.ru/uploads/20120119/gW4x6Mxi.jpg The attempt at a solution I drew the graph. It's a vertical cylinder, with its axis along the z-axis, with the top cut off by the plane z=3 but the cylinder goes down to infinity. The radius of the cylinder is 1...

Homework Statement Three charges with values + 20 μC, -10 μC and -10 μC are placed at the corners of a 0.10m square, as shown. c) Consider a sphere of radius 0.3m which totally encloses all three charges. Using Gauss's law derive an expression for the flux through this surface. Homework...