The emission of the electrons (called photoelectrons) depends on the frequency of the incident light not the intensity of the light, Such that these electrons will not be emitted until the frequency of the incident light becomes greater than or equal to a certain value which is called the critical value (ν c) however is the intensity.These electrons are picked by anode which causes the current in the external circuit.When light falls on the metallic surface, some electrons take enough energy to escape.The photoelectric cell consists of a metallic surface which is called cathode, This wire is called anode to do not hide the light falls on the cathode.It is used to convert the light energy into electric energy as in the calculators, opening and closing the doors and some instructions, It depends on t he emission of electrons due to falling of light on a metallic surface (photoelectric effect). The intensity of the electron beam can be controlled by using a grid in the way of the electrons as well as using magnetic and electric fields (plates X, Y) to direct the bundle of electronsto sweep the screen point by point generating the picture, so, called raster until the frame is completed. The energy (Joule) = Energy in electron Volt × Charge of the electron The energy of electrons (K E) is determined from the relation: K E = ½ m e v² = e V These electrons are liberated from the metal and then picked up by the screen, which is connected to a positive pole called anode, thus causing current in the external circuit, When the electrons hit the screen, they emit light which varies in intensity from point to point on the fluorescent screen, depending on the intensity of the electrical signal transmitted. The tube consists of a metal surface called the cathode, The cathode is heated by a filament, electrons are emitted from the electron gun (E – gun), due to heat, some electrons may overcome the forces of attraction at the surface (surface potential barrier). In solid state design, you generally don't worry about it since transistors have way more gain than VTs, and you don't require output matching xfmrs since transistors are already Lo-Z devices, so you can have enormous open loop gains and big enough feedback factors to linearize them.Cathode ray tube Structure & working method One is that the lighter the load, the better the linearity, as the delta-I is less for any given delta-V. If you have to have some specific gain, about the only thing you can do is split the plate resistor into R P1 and R P2 and scale them to tap off the required voltage such that v o/v i= 10. That leaves design by loadlines, and the main criterion for performance is low distortion, and you take the gain you get. There are various network formulae, but they do you no good if you don't know what values to use with them, and VT characteristics like g m and r p can vary widely with plate current. These kinds of formulas don't apply to hollow state. (There's a comparable formula for FETs as well) If you wanted a BJT voltage amp where A V= 10, that's simple:Ī V= R C/(R E + r e) and done. Hollow state design isn't done by formula like it is for solid state.
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