Cathode Definition and 125 Threads

Hello All : i had few suggestions about battery enhancement using some ideas which i had just abstract understanding not enough even to suggest discussion but i have this question why we dont fold the anode and the cathode into geometrical shape , wouldnt that increase the number of...

I read in the following book A history of the sciences by Stephen F. Mason. About the discovery of the electron the write what I attached in the picture. I wonder what do these positive rays traveling in the opposite direction they talk about consist of? Some ions or what? I understand that the...

I really tried to solve it a lot and the info that I gathered is : Electrons or protons can be ABSORBED by cathode or anode so there must be some hole in the electrode for the rays to pass. These electrons ionize the gas and those positive gas ions move towards cathode.

The attached diagram shows the cathode rays moving in straight lines forward but the anode is beneath them?

We know anode=oxidation=loss of electrons and cathode=reduction=gain of electrons but in the photoelectric effect the electrons are gained at the anode and lost at the cathode of the discharge tube? References: Anode, Cathode, Oxidation, Reduction

I am wondering about an exercise exam question (it isn't homework): "at low temperatures (<2000 K), thermionic emission of a tungsten cathode depends on tunneling. By coating the tungsten with a suitable substance, the emission by tunneling can be greatly increased. Question: which two...

Hello, In cathode ray discharge tube,negative electrode is cathode and positive electrode is anode. But in case of direct current circuit, it is the positively charged terminal of a voltaic cell or storage battery that supplies current and anode is the negatively charged terminal of a voltaic...

I know typically the hot cathode of an electron gun or vacuum tube is heated either directly or indirectly by electric resistance heating. What if the tungsten (cathode) were heated by another means, say focused sunlight? Electrons would still boil off through thermionic emission. If a small...

I've attached a picture from the problem, the given equations, and my work so far. I knew I had a problem when My units wouldn't check out. This should just be simple algebra but It's not working. Please help me to understand what I am doing wrong.

Good Day, I would like to obtain cathode-ray tubes for deflecting electrons with a magnet. However, I don't want to deal with X-rays, and would prefer to obtain cathode tubes that cannot produce X-rays at all. I haven't had much luck on the internet finding such cathode ray tubes or I don't...

Homework Statement The accelerating voltage in a cathode ray tube is ##1000 V##, the electron current density is ##150 \mu A##. a) How many electrons arrive at the screen in a second? b) What's the magnitude of the force exerted on the screen by the electrons if they stop on collision? (Sorry...

I am trying to understand the "strong" negative E field in the Aston Dark Space in the thin region close to the cathode or else even the cathode surface. See the diagram at: http://www.glow-discharge.com/?Physical_background:Glow_Discharges My question regards the "Electrical Field E" graph...

So, I'm new to electronics and I started to build some circuits with LEDs. I read up on how LEDs work and how they consist of a doped semiconductor material etc. But when I actually went to wire the LED in, it said the anode should be connected to the positive terminal of the power source. I'm...

So, I'm a little confused on how batteries work. I understand they convert chemical energy into electrical energy. I also understand that the battery consists of an anode and a cathode with an electolyte in the middle to force the electrons from the chemical reaction to have to follow the wires...

I am trying to understand the working of simple hydrogen fuel cell. We have anode (negative terminal), cathode (positive terminal), catalyst at anode to separate negative and positive ions of hydrogen atoms and electrolyte which allows only positive ions. We will be sending hydrogen fuel at...

Hi I'm running an experiment where I want to see the electrical field generated when I energise a submerged anode (an array consisting of 4 x stainless steel tubes spaced equidistance apart) and cathode array (similar to the anode) upstream and downstream of the flowing water tank (glass sided...

Light bulbs and cathode ray tubes are structurally similar in some respects. For example, both contain a filament -- in the light bulb, the filament heats up to produce light, while in a cathode ray tube, the filament emits electrons, which are then steered into a target (in a CRT TV, the...

Homework Statement Question: A cathode ray tube in a TV has an electron gun operating at 10 kV. a: What is the velocity (in m.s-1) at which the electrons are emitted? Answer:5.9x107 b: How many volts are needed between the deflector plates to move the beam impact spot across a 70 cm screen if...

what if i have a cathode at one end of a tube and multiple anodes through out the tube with argon gas, will electrons flow from the one cathode to multiple anodes like curves -ve1 to +ve1 and -ve1 to +ve2 and -ve1 to +ve3 or there has to be only one cathode and one anode for electrons to flow (...

Homework Statement A photon with the length of lambda hits a cathode perpendicularly to its surface. As a result, an electron leaves its surface perpendicularly to the direction of the photon. How much momentum was transferred from the photon to the cathode? The work function of the cathode is...

Homework Statement What is the distance Δy between the two points that you observe? Assume that the plates have length d, and use e and m for the charge and the mass of the electrons, respectively. Express your answer in terms of e, m, d, v0, L, and E0. Homework Equations kinematics...

Homework Statement What 3 materials is the cathode coated with, from which the electron originate? Homework Equations None The Attempt at a Solution From what I managed to find, I think some may be nickel and barium but I'm not sure.

There is a cathode to ground resistor on a KT66 power tube on a amp kit. The value is 1 ohm. I ASSUME the only reason for it being there would be to be able to measure the current flow. I ASSUME 1 ohm is not going to change the cathode bias. Is my assumption correct? The KT66 is a beam power...

I have recently studied about relativity being the reason for magnetism. The example given was about a magnetic field generated from current down a long wire. When two such wires with current in the same direction were parallel to each other there was an attractive force between them because...

Homework Statement You need to design a photodetector that can respond to the entire range of visible light (400 nm - 700 nm). What is the maximum possible work function? Homework Equations E = hf = hc/lambda The Attempt at a Solution For 400nm, I got E = 3.11 eV and for 700nm I got 1.78 eV...

I was wondering if I breakdown water with a carbon electrodes, will some methane be formed as well as hydrogen? In addition if methane is formed could other hydrocarbon chains also occur?

I know that cathode rays follow a helical pattern if they enter a uniform magnetic field at an angle less than 90 degrees. This leaves me with two questions. 1. If the cathode ray described above, hit a phosphor coated screen, would it show only 1 spot or a circle? 2. If the magnetic field was...

suppose I connect a 10,000 v supply to a normal tube light. what will happen? will it behave like a cathode ray tube or something else

How do CRTs work well and electrons can be sent to exact location on screen in CRT monitors if electrons can behave like wave? Is there something in old TVs (for example measurement device) along the road that electron travels to avoid behave like wave?

I would like to calculate the electron kinetic energy ejected from a cathode as a function of the electric field and pressure without known of the temperature and velocity.

What causes these striations? How does the voltage and pressure of the discharge affect the size, color, number, and spacing of the striations? I have produced a discharge with striations with fairly low voltage (under 15kv) and pressure 10 - 100pa, and the striations are very thin, compact, and...

Homework Statement A cathode ray tube (CRT), consisting of an electron gun and a screen, is placed within a uniform constant magnetic field of magnitude B such that the magnetic field is parallel to the beam axis of the gun, as shown in figure...

Why Na+ (which is positive in charge) migrate to the cathode which is also positive in charge?? They should repel each other right?

I have just learned about the cathode ray tube in the class room. There is a part called electron gun in it which emits electrons and these electrons finally strike the fluorescent screen.(I hope its correct till here.) But I want to ask that won't there be a loss of electrons in this process...

Homework Statement A solenoid is placed beneath a CRT that produces a magnetic field of 1.10 x -2. The CRT is 1 meter away from a screen. The electrons that make up the beam were accelerated from rest through a potential difference(V) at the beginning of the CRT. Acceleration of the electrons...

For my year 12 physics EEI (extended experimental investigation) i need to develop some sort of experiment with variables i can change to retrieve data from. I have a basic cathode ray tube from a few months ago much like the one in this video: . Does anyone have any idea of what variables i...

In our textbook it is written that -voltmeter measures the electrode potential difference between 2 half cells (in an electrochemical cell) (electrode potential refers to the potential difference between electrode and its salt solution in which it is dipped) it should come-voltmeter measures...

I was studying about dry cell and read that carbon(graphite) rod surrounded by MnO2 is used as cathode but when i read the chemical reaction equation at cathode given as : MnO2 + NH4+ + e - - - - > MnO(OH) +NH3 I nowhere found carbon... So where is it actually used? (i found this for mercury...

Hello all. I have been looking at this problem: I wrote three equations there, one for each part, which I think will help me solve each part; is my approach to the problem using those equations that you see there correct? I am just looking for some advice on where and how to start this problem...

I don't know a lot about classical physics but I was wondering how many volts a cathode ray tube emits?

I have a question which has intrigued me for quite some time. If the electrons are accelerated using a potential difference in a cathode ray tube, the electrons should get accelerated till the time they reach the anode only. Once they cross over (ie. move to the other side of the anode), they...

How cathode is positively charged in voltaic cell?I mean at cathode reduction takes place ,but the electron which is gained for reduction comes from anode,than why cathode becomes positively charged ?As electrons are from anode not from cathode that means electrons are not lost by cathode ,so it...

Hello everyone from the Physics Forums, I'm doing a school project and I'm looking for a potential anode alloy that is ferromagnetic which I could use with a copper cathode. I'm making a battery and I have to use copper as my cathode mainly because I have made the cathode cells structured...

This is a list of ferromagnetic materials that I've found on Wikipedia's category ferromagnetic materials page. I was wondering which of these materials would make possibly great cathodes for aluminum anode in the application of creating an sulfuric solution based acid battery. The battery I...

Hi! I've been watching this video http://ocw.mit.edu/courses/chemistry/5-111-principles-of-chemical-science-fall-2008/video-lectures/lecture-2/ on the discovery of electrons , and I have some doubts about it. The lecturer explains the cathode ray experiment performed by J.J Thomson. This is...

I am studying thyrisors right now. I am really struck at trigger circuit . The book shows gate source voltage and gate chathode voltage as two different things. I fail to understand the difference and significance of them. Please help me out .

Hi. I am a complete novice working on my first backyard experiment. I have a 1part sulphuric acid 4parts tap water pregnant leach solution (from old copper mine tailings). If I were to set up an electrolysis type experiment with a lead anode and a copper cathode should I expect all the...

If I were to strike an arc between a copper cathode and a tungsten anode would copper be deposited on the anode? If so how could I calculate deposition rate? I know this works in electroplating but will it work through air or another gas?

My question is simple: Why do batteries need electrolytes? Wouldn't the battery need the charge to flow only through the circuit in the device being powered? The point of the anode and cathode's separation is to preserve the potential difference, so why allow charge to flow through an electrolyte?

Homework Statement I am building a CRT for my physics project but have some doubts. I know there will fluorescence effect but my project requires to do an experiment and make observations. So how can I relate this experiment so that I have:- 1. Different cases and experiments with the CRT...