Homework Statement
Homework Equations
Flux = ∫E.ds
The Attempt at a Solution
I need to get the projection of cone on a plane perpendicular to the electric field . The area thus obtained when multiplied by electric field would give the flux .
I am not able to imagine the projected area...
I've been studying em induction and in my book it was explained by considering a metal rod of length l moving through a magnetic field and cutting through the field lines at a constant speed. So in time dt it moves through ds and they showed e=BA/dt, where A = l x ds(the area that the rod...
Homework Statement
A circular area with a radius of 7.90cm lies in the x-y plane.
A. What is the magnitude of the magnetic flux through this circle due to a uniform magnetic field B = 0.223T that points in the +z direction?
B.What is the magnitude of the magnetic flux through this circle due to...
Homework Statement
The following equation is presented in my textbook, with very little context and J is simply described as the "trans-membrane fluid flux, which can be modeled by using Darcy’s law."
Typically in this bioseparations class, when we discuss permeate flux, it is a unit volume...
Homework Statement
My book demonstrates how a uniform electric field through a box generates a net flux of zero. I was wondering if the same would happen from a point charge outside of the cylinder on one end instead of a uniform electric field.
Homework Equations
Flux = E⋅A
The Attempt at a...
Homework Statement
[/B]
A simple model of a railgun is a metal bar which runs on two long parallel rails. The two rails are connected to a charged capacitor with capacitance C and a resistor with resistance R. After charging, the capacitor can discharge through the circuit. You may assume that...
I wasn't sure where to put this so mods feel free to move,
So this is a problem I'm trying to solve for a masters project and simplified it is this;
I essentially have a stack of magnets all separated by 4mm each magnet is identical and produces a magnetic flux of 17.5 gauss at its centre (all...
Hello, all. I have been working on the following problem and was wondering if someone could check my work and provide some valuable input:
Here is my work:
What do you guys think about my approach to this problem?
My reasoning:
The magnetic force on charge q is
Fm = qv x B
B does not change |v|. Therefore, |Fm| is constant at time t > 0 and Fm is always perpendicular to the direction of movement of charge q. Fm behaves as a centripetal force, and thus the charge moves along the circumference of a...
It is a cylindrical ac machine. If we want to produce a sinusoidal voltage, we need B (magnetic density) to vary sinusoidally.
To get B vary sinusoidally, we need to get H(magnetic intensity) to vary sinusoidally.
To get H vary sinusoidal, the best way is to vary the numbers in the air gap...
I'm messing around with Faraday's Law of Induction, and I will be using two magnets attached either side to a small bar inside two coils of copper wire, which I spin to induce a current. The design is basically this:
http://amasci.com/amateur/coilgen.html
My question is, what shape for the...
Hello!
Im having some trouble really understanding this concept. I'll summarize my difficulty in 2 situations that I struggle with:
1) Coil: The inductance of a coil with N turns is known to be proportional to N2. My question is why is that true? I know that the H-field (and therefore the...
Homework Statement
Let ## E ## be the ellipsoid:
$$ \frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}+z^{2}=1 $$
Let ## S ## be the part of the surface of ## E ## defined by:
$$ 0 \leq x \leq 1, \ 0 \leq y \leq 1, \ z > 0 $$
Let F be the vector field defined by $$ F=(-y,x,0)$$
A) Explain why ##...
Measuring the total radiant flux with an optometer of SFH 4550 LED from osram I'm getting ~70mW,
If I place 5mm long rubber hose around the led (top 2,5mm of the led is free), the power is reduced to 50-40mW.
This does not make sens to me, the led has a half angle of ±3° and emits nothing to...
Hi,
If you've got an arbitary magnetic Flux1 and Flux2, traveling in the same or opposite directions, through a core, it doesn't matter with regards to the point on the saturation curve does it? Opposing or in the same direction it'll still be at the same point on the mag curve won't it?Thanks...
I found that for some LED's manufacturers specify groups/classes of radinat intensity in their datasheets.
For example SFH 4258 from Osram http://www.osram-os.com/Graphics/XPic0/00101891_0.pdf/SFH%204258,%20Lead%20%28Pb%29%20Free%20Product%20-%20RoHS%20Compliant.pdf
has four groups, going from...
I understand that from KVL
e = v -IaRa
e=k(flux)speed
speed=(constant)*(V-IaRa)/flux
But physically what causes the speed to increase?
What force causes the rotor to accelerate?
In fact physically, the rotor is moving because of field flux interacting with armature current's flux.
So...
Homework Statement
Mono-energetic sources of neutrons emitting S neutrons/cm^3 sec are distributed uniformly throughout an infinite material (characterized by a macroscopic absorption cross section Σa and a diffusion coefficient D). An infinite sheet of very thin absorber, of thickness t and...
Hi.
Consider the cylindrical Gaussian surface (Gs) shown in the following picture:
Using Gauss's law,
∫ E ⋅ dA= E ∫ dA = Q/ ε
E 2 π r L = λ L / ε
E= λ /(2 π r ε)
Is this true? I have a feeling like this is wrong. We have considered that there is only ONE...
Magnetic flux linkage = BAN
B=magnetic field strength per unit area
A=Area of conductor moved through the magnetic field
N=Number of coils
I don't understand when my physics textbook says the area of a single coil of wire moved through the magnetic field is π×radius of coil^2 as most of the...
Homework Statement
According to my textbook, the electric flux through a disk of radius R situated at a height d from the xy plane is given by:
##2 \pi k_0 Q [1- \frac{d}{\sqrt{R^2+d^2}}]##
Where ##k_0 = \frac{1}{4\pi \epsilon_0}##
I'm having some difficulty obtaining this answer.
Homework...
Homework Statement
The Earth possesses an electric field of (average) magnitude 150 N/C near its surface. The field points radially inward. Calculate the net electric flux outward through a spherical surface surrounding, and just beyond, the Earth's surface.
Homework Equations
Flux =...
My textbook says "the net flux is zero through a closed surface that does not contain any net charge," and justifies it by saying that everything flowing in has an equal thing flowing out. This makes ABSOLUTELY NO sense to me.
This is example 27.2 in my textbook. I have the answer, but it doesn't make sense to me. I understand that if electric field is tangent to the surface at all points than flux is zero. Why, though, does my textbook assume that the ends of the cylinder don't have field lines extending upwards and...
So basically I was wondering whether it's possible to get the expression of ideal gas using molecular flux equation which is ##\phi = \frac{1}{4}\bar{v}n##. The derivation should be straightforward. I need to get the expression of pressure. Because the flux by definition already gives the rate...
Looking for any life expectancy data for water soluble flux going low Z. How long it takes for conductive material to migrate and cause low impedance bridges at any humidity or temperature.
Homework Statement
I am just a little bit confused. I have a question that is asking me to explain what the physical significance of volumetric flux is.
Homework Equations
I am not sure that this problem requires any equations!
The Attempt at a Solution
I know that the flux corresponds to...
Homework Statement
I was given this question.
The wall of a building is constructed of face brick (10cm thick) and concrete block (50 cm thick) with an air filled cavity (5cm thick). The interior and exterior convection coefficients are 8.3 W.m^-2.K^_1 and 35W.m^-2.K^_1 respectively. The...
Homework Statement
Calculate the outward flux of F = 3z\mathbf{e_{\rho}} + cos(\phi)\mathbf{e_{\phi}} + 2z\mathbf{e_{z}} through the base of a cylinder centered at the origin with radius \mathrm{R} and height \mathrm{2H}.
Homework EquationsThe Attempt at a Solution
I am unsure of how to tell...
So I was reading about magnetic semiconductors and I got confused so can you please clarify I will ask a question that is made up of two parts.
Magnetic semiconductors are ...
a) devices that alter or switch on/off electric current flow depending on the magnetic field strength etc applied OR
b)...
For diamagnetic materials, when an external magnetic field is applied, the electrons having orbital magnetic moment in opposite directions spped up.
how does this happen?
The direction of magnetic momwnt is given by right hand thum rule. If there is an electron revolving in anticlockwise...
So far I have only found the initial papers of Deaver, Bascom; Fairbank, William and of Doll, R.; Näbauer, M.
Is there any later and refined similar experiment result?
Homework Statement
I am trying to graph the flux density field between two infinite line charges located at y = 1 and y = -1
Homework Equations
I am trying to do it using the equation for a line charge that I got from lecture notes.
The above equation is derived from this:
Here is the...
Homework Statement
A long cylinder of radius a with magnetization vector M=M_0*(r/a)^2*a_φ. Find the magnetic flux density inside and outside the cylinder.
Homework Equations
J_m=∇×M
J_ms=M×a_n[/B]
A=(μ_0/4*π)*(∫(J_m/R)dv+∫(J_ms/R)ds)
B=∇×A
The Attempt at a Solution
Basicly what I thought...
Homework Statement
An uncharged nonconductive hollow sphere of radius 12.0 cm surrounds a 11.0 µC charge located at the origin of a cartesian coordinate system. A drill with a radius of 1.00 mm is aligned along the z axis, and a hole is drilled in the sphere. Calculate the electric flux through...
I was reading that the ITER will take advantage of the energetic neutron flux by using them and lithium 6 to breed tritium for more fuel, and to use multiple heat exchangers to grab their energy. And just to make sure that I'm reading it right, the main problem with the neutrons will be their...
What is the solution of heat transfer equation when there is continuous heating ( flux of energy) to one end of a metal rod? what will be the temperature profile before reaching the steady state? when I try the boundary condition where one end (x=0) is kept at T1, I got the general solution of...
Homework Statement
I have uploaded a file that shows the question.[/B]Homework Equations
I believe the only relevant equation is: flux = Q(enclosed)/E(knot)[/B]The Attempt at a Solution
Well I have some questions first. The problem statement says that the sphere on the left has a net...
Homework Statement
6 Gaussian cubes are shown below. The surfaces are located within space containing non-uniform electric
fields. The electric fields are produced by charge distributions located outside the cubes (no charges in
the cubes). Given for each case is the side length for the cube...
Homework Statement
The drawing shows an edge-on view of two planar surfaces that intersect and are mutually perpendicular. Surface (1) has an area of 2.20 m², while surface (2) has an area of 3.90 m². The electric field in the drawing is uniform and has a magnitude of 200 N/C. Find the...
We know Total Magnetic Flux B = B_0 + B_m
Where, B_0 is the external field and B_m is the field inside a material.
Now, we get,
B = B_0 + μ_0*M (M is the magnetization)
My question is -
Do I always have to use μ_0 ? If yes then Why?
The material isn't free space, is it?& also
B =...
Homework Statement
If the electric field is constant in direction (horizontal in the x direction) but its magnitude decreases from E1 to E2, determine the flux through a cubical box of side length L if four of the sides of the box are parallel to the field.
Homework Equations
∫EdA = flux
The...
Homework Statement
Using Cylindrical coordinates, find the total flux through the surface of the ellipsoid defined by x2 + y2 + ¼z2 = 1 due to an electric field E = xx + yy + zz (bold denoting vectors | x,y,z being the unit vectors)
Calculate ∇⋅E and then confirm the Gauss's Law
Homework...
So if you have a single inductor then I assume that there is no flux linkage and that L = flux*N / i = L11
and so that flux is total leakage flux. If you have two inductors then the flux leakage is any flux that isn't flux linkage (the self flux is flux leakage).
(flux21 is the flux in 2 from...
Homework Statement
I have a coordinate system, (x,y,z). There is a uniform-magnetic-field of 2.0 T that exists along
the direction of the y-axis. There is a rectangular plane bounded by the points
(3,0,0),(0,1,0),(0,1,1),(3,0,1).
Calculate how much flux is traveling through the rectangular...
Homework Statement
I was asked to 'Use a very simple model to find how the Earth’s temperature should vary with latitude.'
Homework EquationsThe Attempt at a Solution
I was thinking about flux and how this should be proportional to the temperature. So I first thought about the area that is...
Faradays law tells us that a change in flux induces an emf. Now consider the phenomenon of motional emf. It is observed across the ends of an open conductor (ie one which is not in a circuit). It is always discussed in connection to faradays law. Where is the change in flux in the case of a...
I found two ways to solve this problem, but I get two different solutions, it's confusing because I can't see the flaw in wrong solution.
1. Homework Statement
Long cylindrical inductor of diameter D1 and inductance L1 is connected to battery and creates magnetic field B1. Inductor is then...
Homework Statement
Assume I want to calculate the electric flux through a spherical surface centred at point P with radius R which contains a point charge Q, that is not concentric with the spherical surface.
Here, I can no longer assume that ∫∫sEdA = E.A, and I have to calculate the value of...