Ray Definition and 493 Threads

Refraction -- A light ray is incedent on a block of glass at an angle of 30 degrees Homework Statement A light ray is incedent on a block of glass at an angle of 30 degrees,what is the angle of refraction. Given: glass: 1.47 incident angle:30° Homework Equations π1 sin θ1 = π2 sin...

According to the Snell's Law refractive index n21= sin i/sin r, but when we use this equation while having a incident light normal to the surface of lens or any other refracting surface it becomes 0/0. So how can we define Snell's law in this situation?

In Rohlf's Modern Physics textbook it reads: "The value of q/m for the electron determined by Thomson wan substantially smaller than the values of q/m determined by electrolysis, that is, q/m for the electron is much smaller than for ionized atoms. There were two extreme possibilities: (1) The...

If I were to construct a cathode ray tube in which the beam of electrons was focused on a double slit, behind which was a screen of phosphorous, could I create an interference pattern? Could this setup be made at home? I imagine making the slits would be the most difficult part. Or is this...

I've been reading about gamma ray bursts (GRBs) lately and have found them to be pretty interesting. As far as I have read, it appears that we still don't know much about what actually causes them, or rather, how the "internal engine" works. The most popular idea for longer lasting GRBs is a...

From my current understanding, a cathode is an electrode which has conventional current flowing OUT of it (or electrons flowing INTO it) while an anode had conventional current flowing INTO it (or electrons flowing OUT of it). From this definition, I don't understand why the electrode which...

Hi, (I'm not native in English, sorry for if bad English) Some background: As a programmer I got more and more distance with physics. I bought a US x-ray tube off ebay to step to a hobby project that naturally keeps me on with refreshing physics knowledge. After the tube came, I jumped...

Now I am wondering what would happen to the sun if it was hit by the nearest gamma ray burst (I believe the nearest one is 6.7 Light years away). Now I understand that a gamma ray burst is going to be more radiation than what the sun produces in its lifetime. I also know that the sun is just one...

i understand that when we shoot x-rays at a object, it will scatter in accordance to bragg's reflection law. as such we position the detector as per the picture below my question is , for the production of characteristic x-rays, does bragg's reflection law still holds? and why does...

Show that the ray is well defined / independent of ruler placement. Ruler placement postulate says Given two points P and Q of a line, the coordinate system can be chosen in such a way that the coordinate of P is zero and the coordinate of Q is positive. I know you can place ray AB where B can...

Homework Statement Ok so we have been given a diagram of a cathoe ray tube, with relevant data on it. The second question asks to "calculate the speed of the electron, using data from the first question". I need to make sure the answer is correct as it leads into many different questions...

Homework Statement In a cathode ray tube (CRT) used in older television sets and oscilloscopes, a beam of electrons is steered to different placed on a phosphor screen, which glows at locations hit by electrons. The CRT is evacuated, so there are few gas molecules present for the electrons to...

θHomework Statement The sun of (diameter D) subtends an angle of θ radians at the pole of the concave mirror of focal length f. The diameter of the image of the sun formed by mirror is _____ Homework Equations 1/v+1/u=1/f The Attempt at a Solution confused with question. Either i...

I was thinking yesterday about a scenario where a ray of light passes a massive body and is deflected. If I were in a rocket moving at the speed of light along the same trajectory, I should follow the same path through the gravitational field and so should observe the ray of light to be...

Homework Statement Plot a graph of sinθ versus sinθ' where θ is the incident ray and θ' is the refracted ray and use the graph to determine the index of refraction of distilled water, the medium through which the incident ray passes. Draw the graph without including the origin as a data...

Homework Statement White light is incident on a sheet of glass as shown below. Complete the ray tracing diagram. Homework Equations n1(sinx)=n2(siny), where n = the refractive index of the medium. The Attempt at a Solution The ray on the bottom is hitting the glass at 90 degree angles...

When a high voltage is applied across the electrodes of the discharge tube, and the pressure of the gas inside the tube is lowered, the electrical energy knocks out some of the electrons from the atoms. These constitute the cathode rays. How does electrical energy knocks out electrons is...

What material is suitable in windows for hard X-rays? What material would you choose as reflective coating of X-rays mirrors for radiation at 200 eV? Why?

For my advanced physics lab course this semester, I recently conducted an experiment using a hyper-pure germanium detector to measure the energy of gamma rays released upon the formation of deuterium (DF). Essentially, I used a neutron source to bombard a hydrogen rich target (used both...

i need a equation that discrip the movement of laser ray in the tube in a way that it won't get out

I am building a cosmic ray detector and I am following these designs: http://www.lbl.gov/abc/cosmic/documentation/CosmicDetector2-0.pdf I have a few questions for those who may be familiar with this. a) In the parts page (http://www.lbl.gov/abc/cosmic/parts.html) I see that the price for the...

Homework Statement In my honours lab we had to perform the Gamma ray experiment in which we have to measure the operating voltage of a Geiger Muller tube for a radio active source say Cs-137. With this we want to measure the linear absorption coefficients of lead and aluminium. Test the...

What would happen to a star if it took a direct hit from a gamma ray burst? For example if a gamma ray burst from a supermassive black hole at the center of a galaxy hit a star, would the star survive? If so, how would the grb effect the star? If not, would the star explode...

I finally found something about thin prisms on the web I don't understand whether the angle of deviation depends on a the angle of incidence in a thin prism or not? Is the thin prism always in the position of minimum deviation?

X ray production -- doubts in the principle involved Homework Statement In x ray production, air molecules are ionised due to presence of very high electric field within the tube and positive ions are attracted to the cathode C and due to their impact electrons are emitted from the cathode...

Homework Statement Homework Equations Fq=E*q kinematics equations... The Attempt at a Solution The problem is that in the end I get a value ABOVE the mid-axis instead of below. I don't know what I'm doing wrong. Please check my reasoning. Stage 1: While it's in between the plates where...

How much will a ray be "deviated"? So my terrible phys prof presented this question but failed to answer it and I have become very curious of the answer after failing to answer it several times. Here is a quick paint drawing of my question...

Why is it that an electron traveling under the influence of a magnetic field (i.e electron going from left to right and B field going into the page) will travel in the arc of a circle yet when an electric field alone is applied (say up page and the direction of motion of the electron is the...

I'm wondering because the gamma ray photon is smaller yet it has a higher frequency. Is it because the amount of energy that passes a single point in a second for a gamma ray is higher than that of radio waves, since a lot more photons are passing that single point that in other em radiation?

http://en.wikipedia.org/wiki/Near-Earth_supernova So we know that many people are putting hard constraints on the galactic habitability zone based on the presence of nearby supernova/gamma ray bursts. But if they *only* affect the ozone layer, then I doubt that it's as hard of a constraint as...

But if this is so, then in these photographs: http://en.wikipedia.org/wiki/Bubble_chamber http://en.wikipedia.org/wiki/Cloud_chamber the "particle track - line of bubbles" shouldn't be able to be photographed so defined, but blureness should be photographed instead, since-if no lens was used...

When Thompson conducted his cathode ray experiment, how did he know that the negatively charged electrons were so small? He knew that they were deflected in measurable ways by electric and magnetic fields, so he concluded that they must have a very small mass to charge (m/e) ratio. But that...

Homework Statement A cosmic ray travels 60km through the Earth's atmosphere in 400μs, as mesured by experimenters on the ground. a. Calculate the relative velocity between the cosmic ray's intertial reference grame and the Earth's inertial reference frame. b. How long does...

Homework Statement An object is locted 15cm infront of a convae lends with a focal length of 10cm. use ray tracing to determine the location of the image. try to draw to scale i)is the image upright or inverted? ii)is the image real or virtual? iii)use your ray-tracing diagram to...

If I have an object and in front of it there's a diverging lens, and in front of that (furthest from the object) there's a converging lens can I just ignore the diverging lens when ray tracing for the image formed by the converging lens? I figure if I were able to draw an infinite number of...

Homework Statement I am given the object distance and height, and the focal length of the mirror and I must draw the ray diagram. Although this was drawn by a computer program that I programmed, I thought it would be more relevant in this forum, because I believe that the rays are correctly...

one question when we have a unpolarized ray and enters the polarized sheet it becomes polarized right , after that if i want to enter it to another polarized sheet with angle alpha with the y-axis there is a formula to find the intensity of the new light which is proportional to an angle I=I0...

Just a check here... I'm doing some ray diagram practice for optics and I've hit a road block. Hyperphysics is stating that for a concave mirror o is usually negative due to it measured against the direction of light propagation when applied to the mirror equation (below)...

Topology Excluded set << Original text of post restored by Mentors >>

so just about finishing a report on x ray abosprtion on different materials, generally the linear attneuation coefficent increases with atominc number Z. However silver(47) had a lower attenuation coefficent then zirconium(40) despite having the significantly higher value of Z. With some...

A ray in Hilbert State is pure quantum state. All interference terms are supposed to be there. How does the interference work, between what basis vector, components or properties?

Hi, I need to make a project to demonstrate Gamma rays. I have cesium as a source to use and a geiger counter to detect gamma rays. Ideas are welcome!

(Since this is a coursework question and not a homework question, I deleted the template) Both my chemistry and physics textbooks cite cathode rays as having the ability to excite or eject electrons from an atom (e.g., dielectric breakdown, x-ray spectroscopy). How can a stream of negatively...

My interests are in astrophysics, so please forgive my ignorance of particle physics. I've just read Frank Close's book, "Neutrino"---excellent read, I'd recommend it---in which he points out that Ray Davis' first experiments to detect neutrinos from nuclear reactors (with no detections)...

The sun emits radiation in all directions. On the Earth, the rays from the sun are approximately parallel. Whatever side of the Earth is facing the sun at any given time is completely bathed in light. When I look at the sun, I can see it as an object..ie. my eyes can figure out where the rays...

Hi All, How can a high energy (above 1 MeV) gamma ray interact with a protium (hydrogen with only a proton in nucleus)? Does it only ionize it? Does it break it up? Does a chain reaction occur where antiparticles are formed and then annihilated, spitting out another gamma ray? I've been...

Dear Physics Forums, I am currently conducting an experiment on gamma ray coincidence from Co-60. Co-60 decays to an excited state, then de-excited by emitting two gamma rays. The aim is to deduce the angular momentum L of the first excited state. Apparently L indicates the type of...

Homework Statement A small bulb is placed in front of a convex lens. a) Suppose that the bulb is placed as shown. Using all three principal rays, draw an accurate ray diagram to determine the location of the image. Label the image location...

Homework Statement Have a few questions on CRT's. If we are given the accelerating voltage (250V) how would I calculate the kinetic energy of the electron as it leaves the positive end of the charge area? What is the formula for the speed of an electron along the tube (vz) as it leaves the...

Ray diagrams (lenses) urgent problem. I need full explanations. 1. The question An object of height 2cm is placed 15 cm from a thin converging lens of focal length 10cm. Complete the paths of two rays on the figure to show their passage through the lens to the image formed. 2. The...