Cathode Definition and 125 Threads

I've been looking to do a physics project, and since particle accelerators are too dangerous, I was thinking about building a cathode ray tube (CRT) I've done some research about building CRTs, and haven't been able to find anything that gives a complete list of how to build a CRT. Could anyone...

Hello everyone, I have some questions about these rays. And i would be grateful if you could help me, 1- The nature of cathode rays doesn't depend on neither the gas in the tube nor the material of the electrodes. Why? 2-The nature of canal rays depends on the gas in the tube. Why? 3-...

In the cathode ray production experiment, at about .01 mm of Hg, cathode rays travel from cathode and move towards anode and produce fluorescence on the walls near the anode.At the same time canal rays also move towards cathode. But only when you use a perforated cathode, the canal rays...

I'm just having trouble understanding, I get the gist of it though. This is what I know in a electrolytic cell (I may be wrong): The cathode is negative, anode is positive and the current travels from the cathode to anode right? So during electroplating, the anode is the electrode being...

Homework Statement Part a) Deflection of the electron beam in a cathode ray tube television set has electrons accelerated until they have K.E. of 25 keV. What is the magnetic field magnitude required to deflect the electron beam 3.3 cm when the magnetic field is 8 cm long? Part b) When...

hey guys i have put this question to clarify some points on battery anode cathode reactions...let me describe this..if we consider the cell to be two electrodes with in between electrolyte .. at anode one has the situation: metal=metal ion+electron released i.e oxidation takes place..! so...

Homework Statement Pb/Pb2+ and Ag/Ag+ Ni/Ni2+ and Zn/Zn2+ Which one is the anode and cathode? Toward which metal do the electrons flow? The Attempt at a Solution 2Ag2+ + Pb ⇔ 2Ag + Pb2+ Pb is anode and Ag is cathode e- go toward Ag. Zn + Ni2+ ⇔ Zn2+ + Ni Zn is...

I am currently looking into photocatalytic materials. Now I might be over simplifying this process but it my observation that I am just looking at electrolysis but instead of electricity provided by a battery I am using electron hole pairs to generate a potential to do my splitting. My question...

Hi I'm new to the forum, so first I want to say hello to everyone. I have been interested in Colloidal Silver lately, and I have produced it with electrolysis in distilled water with NaCl as an electrolyte. I have used a Silver electrode and cathode for both of these experiments. I...

why current does not flow through gas in discharge tube at ordinary pressure?

During discharge tube experiment, the cathode rays are emitted from cathode at very low pressure...it is said that these rays move at very high velocity(if we apply high Potential Difference between 2 electrodes)...do these rays( stream of electrons) travel in uniform velocity or aren't they...

In a video demonstration (not animation), cathode rays appear as a beam of green light moving from the cathode to anode inside the tube. The demonstrator brings a magnet near the tube and the green beam deflects. This I can understand. What I can not understand is that how the electron beam...

In descriptions of the cathode ray, various sites mention how the ray is formed from a voltage applied to the tube which spawns the ray on sees in the vacuum tube. Could someone elaborate on how a voltage can spawn this beam? As in, where does the potential difference come from and so on...

Why are cathode rays able to penetrate very thin metal films?

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...

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...

A graduate student is trying to develop a flow battery based on aqueous solutions of 1 M Cu2(SO4) and Fe(SO4) (recall that the sulfate is divalent, e.g. (SO4)-2 and assume complete solubility). Given a chart like this : CHART How would I know that I need to select Copper (I) and Iron (II)...

I want to know if there is magnetic field around a cathode ray tube. That is, does magnetic compass deflect when brought close to a CRT ? If so, can this magnetic field (produced by cathode rays) be used to have Lorentz force on a moving charge particle ? Presently, what I think is...

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...

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...

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...

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...

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...

(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...

I'm not even sure if it belongs in here... but my class is assigned to do this lab the objective is to determine that D=Vd/Va{(L1^2+2L1L2)/4d} is correct... so my teacher also want us to do 2 graphical analysis based on this formula I think i found one way of doing graphical analysis (if i...

I know that using diodes in parallel is generally a bad design practice since you will have run away current in one of the diodes since they are not necessarily matched exactly. But is it safe to use diodes in parallel if they're designed as a common cathode part? this is an example...

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...

Part of an experiment involved measuring the intensity of an X-ray beam through a piece of aluminium as a function of emission current of the X-ray source. I originally fitted a linear fit to my data (although it does start to level off at high emission currents). The marker however said that it...

I would like to build a cathode ray tube like this one: http://www.youtube.com/watch?v=XU8nMKkzbT8". It would be pretty damn cool playing with electrons. Do you know any references about this experiment? I mean, How could I build a glass vail and are there standard measures?

Homework Statement The maximum kinetic energy of photoelectrons is 3.14 eV. When the wavelength of the light is increased by 50.0 %, the maximum energy decreases to 1.11 eV. What is the work function of the cathode? Homework Equations Kmax = E elec - E not = hf - hfnot hf =...

Why couldn't Thompson just let one electron fly across the gap before disconnecting the battery and turning off the beam, and then measure the amount of charge deposited on the anode,thus allowing him to measure the charge of a single electron directly?

Hello ,people I don't understand what is the use of Low Pressure and high voltage in cathode rays experiment and why do beams of electrons are produced under these conditions? Thanks in advance...

Hi all I don't know If this is the suitable section for this post.. but at all.. let's see if anybody can make me understand this :):) You all know of course J.J. Thomsons's three CRT experiments... The first one was aiming to prove that the appearing rays and the negative charges...

Why does a cathode ray tube (CRT) require a high voltage to operate?

can i use ni-chrome wire , for my heated cathode on my electron gun , using Thermionic emission , or what would be a better filament to use.

When my Tv shoots electrons from the cathode ray tube , where do these electrons come from and is it ionizing whatever they come from.

Homework Statement A conductor is aligned with Earth's magnetic lines of force. The compass set above the conductor points in a line parallel to the conductor. A DC power supply is connected to form a closed circuit with the conductor. Explain how this information could be used to identify the...

Hi everyone. I have studied Lanthanum Hexaboride (LaB6) cathodes the last few days, but I have a few questions regarding them. There are two types of these cathodes; the flat one and one which is in the shape of a cone. I have attached two documents which handles about these two types of...

Homework Statement In an old TV cathode ray tube, electrons are accelerated by a potential of 15 kV between the gun and screen. Find: a) Kinetic energy of the electrons when they reach the screen b) Its respective wavelength c) Wavelength of the photons with maximum energy that are...

Homework Statement A CRT is placed in a uniform magnetic field B, with the axis of the tube parallel to the lines of force. If electrons emerging from the gun with a velocity v make an angle θ as they pass through the origin O so that their trajectory is a helix, show that a) they will touch...

A) In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.22 x 10−17 N during the first 2.00 cm of tube's length; then they move at essentially constant velocity another 46.5 cm before hitting the screen. Find the speed of the electrons when they...

I learned from a website that cathode ray tubes fire electrons from an "electron gun" at the cathode towards the anode, hitting a piece of metal and produce cathode rays in the process. My question is; how do cathode tubes "shoot" electrons? Apparently it's due to a high potential difference...

If direct current is applied to activated carbon, will it be drawn to the cathode?

Homework Statement The figure from the link below shows a cross section of a cathode ray tube. An electron in the tube initially moves horizontally in the plane of the cross section at a speed of 2.0 x 107 meters per second. The electron is deflected upward by a magnetic field that has a...

"Plating" Metal - Cathode or Anode? Homework Statement You want to plate out nickel from a nickel (II) nitrate solution onto a piece of metal inserted into the solution. Should you use copper or zinc or can you use either of these metals? Homework Equations Standard Reduction...

Homework Statement This is from a lab question, but i think i did it right, i would just like some confirmation. I had to make an electochmical cell for a lab, (actually mutiple ones) but it asks me to find the anode, cathode, and which chemical underwent oxidation and reduction. If you have...

Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 5710 V. It then passes between two horizontal plates 6.45 cm long and 1.24 cm apart that have a potential difference of 249 V (see figure below). At what angle q...

How does a cathode heater work? Can't seem to find a straightforward explanation anywhere.

anode vs cathode? Hello everyone :) I am having a problem understanding the difference between the anode and cathode in electrochemistry. What I know so far is that the anode is the electrode at which oxidation takes place (and hence donates electrons) and the cathode is the electrode at...