Index Definition and 795 Threads

Hello. Given a binary system with two identical components (in particular de B-V index of both is the same), how would you calculate the B-V index of the system? and, how would it change during eclipses? I have my own answer, but want to contrast it against yours.

Had this question in a test today, :). Homework Statement Carbon tetrachloride (n = 1.46) is poured into a container made of crown glass (n = 1.52). What's the speed of light in the liquad? Homework Equations v=c/n The Attempt at a Solution I just multiplied 1.46 by the...

My textbook says it has been proven that the refractive index of a medium is a ratio between the speed of light in air or vacuum and the speed of light in a medium. It says that the ratio is the same as sini/ sinr . But isnt't it the inverse? And, can someone please explain this law to me In...

1. The refractive index of the Earth’s atmosphere is n = 1.01 + α(R − r), where α is a constant, r is the radial distance from the Earth’s centre and R = 6.4 × 10^6 m is the Earth’s radius. By considering a path comprising a series of total internal reflections or otherwise, find a value of α...

ive been trying to proof the modulation index for Am transmission, it goes like this Vmax = a(1+u) Vmin = a(1-u) it basicilly describes the amount of infromation in the total power transmitted and should allways be between 0 & 1 eventually the answer should come out to be u =...

Part A i just need to know if i have done it properly. Part B is done Part c don't have a clue :cry: Homework Statement Homework Equations Law of refraction n1*sinχ1=n2*sinχ2 Critical Angle sine(x) = nr/ni The Attempt at a Solution part a is on the image above part b I have done it...

I'm encountering subscripts of the form x_{\alpha_{i}}, where i\in \mathbb{N} , increasingly often in Real Analysis. Is the purpose of the double subscript to show that the index is countable? Another thing that seems to make sense is that the subscript of the index is to define an order on the...

hi, i have seen on another topic here that the refractive index equals the square root of the dielectric constant. from datasheet values we have... water refractive index = 1.333 dielectric constant = 80.1 Without even doing the calculation its obvious that the square root of 80.1 is not...

Homework Statement Monochromatic light of variable wavelength is incident normally on a thin sheet of plastic film in air. The reflected light is a maximum only for 482.9 and 676.0 in the visible spectrum. What is the minimum thickness of the film ? Homework Equations 2nt=m*lambda...

Homework Statement What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 520 ? The index of refraction of the film is 1.34, and there is air on both sides of the film. Homework Equations Im wondering do I...

Hi Some of my students are doing an experiment, investigating the refractive index of different liquids such as water, alcohol, syrup (very concentrated sugar solution!), and oil. The results that of their experiments seem to be showing that oil has a high refractive index than water and...

Homework Statement How many subgroups of index 10 are in \mathbb{Z}_{20} \times \mathbb{Z}_{9} \times \mathbb{Z}_{35}? The Attempt at a Solution So I figure the order of this group would be 20 x 9 x 35 = 6300, and so any subgroup of index 10 would have order 630. By the fundamental theorem...

Let g_{ij} be a tensor, where 0 \leq i,j \leq n. The Morse index \mu is the number of negative eigenvalues of g. On page 469 of Eberhard Zeidler's QFT III: Gauge Theory, it says that g is Riemannian if \mu = 0 and pseudo-Riemannian if 0 < \mu < n. Is this correct? If so, what kind of tensor is...

I have read somewhere that we can extend the notion of a series of a sequence \sum_{i=1}^{\infty} a_n to sums over an arbitrary index set, say a : I \to \mathbb{R} is a family of real number indexed by I, then \sum_{i \in I} a_i is the sum of all the elements. I think the text...

Hi. In the textsbook i raed for frequencies that (real part of index refraction) |n|~1>>|K| (exitinction coefficient), we have transparent matter (weak absorption). If we have a bulk matter with big diameter, that there are no transmitted light ( i don't know it is possible or not), our matter...

Index of subgroup H is 2 implies... Homework Statement Just had my abstract algebra test. This was the only question I did not answer. The rest I answered somewhat confidently. Prove that if H is a subgroup of G, [G : H] = 2, a,b are in G but not in H, then ab is in H. Homework...

What is the relationship (a mathematical one) between the density and the refractive index of a medium?

Homework Statement Attached as pdf. Homework Equations Attached as pdf. The Attempt at a Solution I know that refractive index is given by n=\sqrt{\varepsilon} normally. But is it still the case when asked for n( \omega) ? If so, I've tried rearranging equation 3 for...

Is the index of refraction for LCP/RCP light any different from that for linearly polarized light?

Is Tab\partialcf = Tac\partialbf, where T is a tensor? Seems to me like you should be able to do this: Tab\partialcf =Tab\deltabc\partialbf =Tac\partialbf Maybe I'm using the Kronecker delta incorrectly. Could someone check this for me?

Homework Statement Is anyone familiar with the effective index method for rectangular waveguides? I have a waveguide for which the width is much greater than the thickness. I think I need to start by treating it as a planar waveguide. But I am supposed to get an effective index which depends...

Situations that Require the Accurate Determination of Refractive Index

I haven't learned much of advanced mathematics. It seems that we can use metric tensors to lower or raise index of christoffel symbols. But isn't christoffel symbols made of metric tensors and derivatives of metric tensors? How can we contract indices of a derivative directly with metric tensors...

why do refractive index vary with the wavelength?what makes the relation between wavelength and the refractive index reverse relation??and what makes the relation between frequency and wave length direct relation??does it has somethin to do with energy and the abiliy to penetrate bodies??Are...

A plane wave can be described by the real part of the exponential wave equation: \mathbf{E}=E_{0}e^{i(kz-wt)} Adding the subscript i or r for incident or reflected waves, the ratio of the amplitude of reflected to incident wave is given by: \frac{E_{r0}}{E_{i0}} =...

what does refractive index depend upon? The answer of my textbook is "wavelength" so how,although it cannot be controlled directly?? I thought It depends on the speed of light in the media I don't understand how to answer these kinds of questions for example :what does the deviation angle...

[PLAIN]http://img843.imageshack.us/img843/6831/dsc00723mm.jpg a light ray falls on parallel layers made of transparent materials which have different refractive indicies so ,what does the ratio sin(fi 1)/sin(theta 4) depend on? 1-n1,n2 2-n2,n3.n4 3-n1,n2,n3,n4,n5 4-n1,n2 could you...

http://www.fiberoptics4sale.com/Merchant2/fofs_img/how-optical-fiber-works.gif The refractive index of the core is higher than that of the cladding, I don't understand why!

I'm not understanding how to setup/pictorialize this problem. I've done several very simple problems determining the index of refraction, but I'm confused on this one for some reason. http://i111.photobucket.com/albums/n149/camarolt4z28/Untitled.png

I have a plastic disk 0.5" in diameter whose radius of refraction is supposedly non-uniform. It will vary by 0.015 at most from the center to the outside. I need to come up with some method of measuring the refractive index locally. I have access to: helium neon laser a photodetector and...

If a light travels from A to B and there's a plane of glass in between the two points, will the total time it takes to make the journey be different than if there was no glass? If light slows down in glass, then I guess the answer would be yes, but I've read that the index of refraction is more...

Hello, Say we have field (F,+,.) and field extension (E,+,.), then the degree of the field extension (i.e. the dimension of the vector field E across the field F) is given the symbol [E:F] . But we can also see F and E as the groups (F,+) and (E,+), and then the same symbol denotes the...

I have to prove that every subgroup H of a group G with index(number of distinct cosets of the subgroup) 2 is normal. I don't know how to start :'( Please help.

Homework Statement Simplify the following expressions involving the Kronecker delta in N dimensions. Where possible, write the final result without indices. C_{ns}\delta_{rn} Homework Equations The Attempt at a Solution I know Kronecker delta is symmetric but that doesn't seem to help. Is...

whats the relationship between the temperature of water and its refractive index?

I'm a Matlab newbie. I have an array of strings, for example: header = {'Fred', 'Tom'} When I do: header(1) I get 'Fred' I want to be able to change elements--for example: header(1) = 'Jill' But I get this error: ? Conversion to cell from char is not possible. I would be...

I am modelling a radio wave propagation simulator for a Wifi at 2.4 Ghz. I know that the refracted index of glass for light is around 1.5, how do I translate this to a 2.4 Ghz radio wave. And what about other materials, such as concrete, brick wall etc. Thanks.

Homework Statement The conductivity of a plasma is defined as \sigma = i\frac{Ne^{2}}{m\omega} where N is the electron density. a) Prove the refractive index is: n = \sqrt{1- (\frac{\omega}{\omega_{p}})^{2}} with \omega_{p} = \sqrt{\frac{Ne^{2}}{m\epsilon_{0}}} b) Show the Attenuation...

Hello all, I'm new, so please go easy on me if this is a silly question. If I have a source set of characters, say: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~ " And I compute the Cartesian product of this source set (sort of). This gives...

Homework Statement This is from hand and finch. We proved in the previous problem that (using euler lagrange equation): x=\int_0^y\frac{dy}{\sqrt{\left(\frac{n[y]}{n_0}\right)-1}} where n_0 is the refractive index at y=0 and x=0. The ray enters horizontally. As an actual computation...

Could you please tell me what means B_{[ij} B'_{kl]} where B and B' are bivectors I found it in http://arxiv.org/abs/hep-th/0311162" look at lemma 2.4 thanks

Homework Statement a ray of light traveling through glass is incident at the interface with air at an angle of 30 deg to the normal. if the ray is refracted at the critical angle, what is the refractive index of the glass? Homework Equations none The Attempt at a Solution sin...

Refractive index is defined as n = speed of light in a vacuum / speed of light in medium Since both speed of light in a vacuum and speed of light in medium are real number, refractive index also has to be real. But we know that in general refractive index is complex. So what actually is...

Homework Statement Problem: Sea water has k = 80 in the low frequency limit. Yet its refractive index is around 1.34. Explain the discrepancy Homework Equations For a non magnetic dielectric medium, the absolute refractive index in the low frequency range, is given by : n = √k...

I like Penrose's Abstract Index Notation very much. I am familiar with using Abstract Index Notation to denote Coordinate Basis. But when I try to denote tetrad with Abstract Index Notation, I meet problems. How to denote tetrad in Abstract Index Notation?

I'm stuck on a homework problem. It states the wavelength is 600 nm and the glass lens has an index of refraction of 1.40. Find the index of refraction for the coating and the required thickness. I've googled around, but I'm not sure what equations I should be using. I got 1.183 for the...

I would like to ask a few questions. Does a table of refractive indices of materials at rf frequencies (say for TV) exists? Is there a way for me to estimate it for some materials? Are the refractive indices of these materials higher? Will those materials have low absorption losses at these...

Homework Statement This was for a lab experiment, and I'm still not sure how this all fits together. We were supposed to use snell's law to find the index of refraction for the lab bench. We measured from the top of the bench to our eye level, and to the center of the bright spot seen...

Homework Statement Let’s say you have a transparent crystal sphere, on the far side you cast colored glass. By choosing the right refraction index, the image of glass corn would appear located at infinity (when you look from the other not colored side). Suggest a refraction index...

Homework Statement In a lab we did, we verified Snell's Law of Refraction by measuring the index of refraction for water. We filled a plastic half-circle with water and drew a line normal to the flat side. We measured an angle 30 degrees from the normal line (called the incident ray). We...