Cavity Definition and 275 Threads

Homework Statement A point charge of -2.09*10^(-6) C is located in the center of a spherical cavity of radius 6.54 cm inside an insulating spherical charged solid. The charge density in the solid is 7.36×10^(-4) C/(m^3) . Calculate the magnitude of the electric field inside the solid at a...

Homework Statement The electric field inside an empty cavity in a conductor is zero. Is this statement true no matter what the shape of the cavity? Why or why not? Homework Equations Electric field equation. E = kQ / R^2 The Attempt at a Solution I can't seem to figure out if this...

I am attempting to make a cavity microelectrode in which i will test the electro chemistry of polyaniline powder before moving on to other chemicals. I have read numerous papers on the subject. I am having a major setback in my aim: i need contact between my gold wire and the voltameter (as...

Suppose one has a solid metal body (in static eq'm) with a cavity inside it. Assume the cavity has no charge in it. This is how one could prove that there are no fields inside the cavity: choose two points A and B, both in the solid part of the metal body. Follow a path through the metal...

Inside a spherical cavity centered at the Earth's centre, the space-time curvature is 0 or =/= 0? I know Newtonian gravitational field is omogeneously 0, so no field variation, but does GR give a different answer?

A positive charge Q = 2800.00 C is uniformly distributed over the volume of a sphere of radius R = 6.00 m. Suppose a spherical cavity of radius R/2 is cut out of the solid sphere, the center of the cavity being a distance R/2 from the center of the original solid sphere (see figure). The cut-out...

Im studying gain saturation for homogeneous and inhomogeneously broaded transitions. Im a little confused bout the logistics of laser operation regarding the gain in the cavity. So from ground state, the atoms are optically pumped to produce population inversion(4 level system) where...

I have a quick question. I recently did an E&M problem in which I was given a cylindrical conducting wire of radius a, in which someone bores an off-center cylindrical cavity of radius b (the center of the smaller circle is offset from the center of the wire by distance d). I'm asked to find...

Suppose I had a uniformly charged sphere of some density, inside this sphere at some position there is a cavity of some radius. If I wanted to then find the Electric field somewhere, like say the surface of the sphere, how would I approach the problem? Heres what I did. I pretended the cavity...

In reading about the “Ultraviolet Catastrophe” in dealing with black body radiation, my book says that at the ultraviolet frequencies and beyond, the Rayleigh-Jean equation for the energy density of the radiation would be infinite (and thus a catastrophe). If this is the Rayleign-Jeans...

Homework Statement If we have a cavity filled with black-body radiation, an this is placed onboard a relativistic rocket (uniform linear motion). I want to yield the transformation laws (from the proper frame S' joint to the rocket and moving with constant velocity V in respect to a coordinate...

Homework Statement The textbook claims 'An air caivty between a brick outer wall and the inside wall helps to insulate from heat and cold.' It asks to explain in terms of heat conduction. Homework Equations noneThe Attempt at a Solution Is it because it takes a certain amount of energy to get...

Hello folks, I would like to know whether or not the cavity axial-mode frequencies have any influence on the frequency output of the laser beam. I suppose that the atomic transition from excited state to ground state is the only occurrence responsible for the wavelength, whereas the axial-mode...

Hello, I need help with this problem, Find radiosity B as a function of coordinates (x,y) over a V-shape or rectangular cavity. Consider the two walls and the surroundings to constitute an enclosure. Without any loss of generality, the cavity can have a unit depth. The temperature and...

Hi all My question arises in the context of a photon which is emitted by an atom located inside a cavity. From quantum mechanics, a photon is a quantum of an electromagnetic mode, but we also use the definition which says that the photon is what is released by an atomic system when its...

In the context of properties of conductor & 1st Uniqueness theorem, Griffiths proves that field inside a cavity( empty of charge) within a conductor is 0. Is the result same if we place a +q & a -q (so that Q(enc)=0) suspended in air inside the cavity?

A positive charge Q = 1400.00 C is uniformly distributed over the volume of a sphere of radius R = 10.00 m. Suppose a spherical cavity of radius R/2 is cut out of the solid sphere, the center of the cavity being a distance R/2 from the center of the original solid sphere (see figure). The...

I got a HeNe tube with a constant size which has a concave mirror at one end. Im changing the distance of the other mirror from the tube.. now, i know some distances arent stable, but appart from the Heaviside function, is there any other change in the beam's strength? the only thing that...

Does an electric field exist in the center of a cavity inside a sphere? Can I just apply Gauss's law and say that because no charge is enclosed, the electric field is zero? If not, why can Gauss's law not be applied? Thanks, positron

I am thinking over this, there are two spherical cavities in the interior of a neutral conducting sphere.the cavities have point charges qA and qB respectively at their centres. What will happen when we bring a third charge near the sphere...

This might be a bit to specalised for some of you, but i am trying to calculate the number of modes that light can propegate in a material. The question is as follows Consider a cavity that is a cube with the side length a = 1mm filled with water (refractive index(n) 1.33). Calculate the...

Why is the density of standing waves in a cavity G(f)df=((8*pi*f^2)/(c^3))*df? Also that formula looks weird... doesn't look like it has anything to do with density...

I tried to calculate the casimir force. I need to know if the way I doing it is correct. So I note some steps: 1. I calculate the energy in the space without the plates 2. I calculate the energy between the two plates And then I speculated. I thougt of taking the difference of one and two...

I have been working on an experiment that uses double exposure holography to determine sub-micrometer displacements. [see attached picture for details] It turns out that the optical path lengths LRP and LOP do not have to be exactly but roughly equal for the light if you want the light from R...

I have a question regarding fluids A small sculpture made of gold (density of gold = 19280 kg/m^3) is believed to have a secret central cavity. The weight of the sculpture in air is 25.76 N. When submerged in water, the weight is 23.86 N. What is the volume of the secret cavity. (Density of...