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A heated metal in a vacuum with an electrical charge can emit electrons. The filament is the part of the tube that gets hot. Some tubes use electrons emitted from the filament. Others use the filament to heat a metal cathode, causing it to emit electrons. The electrons flow to a positively charged "plate" electrode through the vacuum.
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∙ 13y ago
Wiki User
∙ 9y agoYes.
Initially described as "cathode rays", electrons were observed being emitted from the cathode (negative terminal) in partly-evacuated tubes, then in fully-evacuated tubes. The partly-evacuated devices used gaseous discharge (ionisation) and were known as "Crooke's Tubes".
Fully-evacuated tubes demanded a heated cathode to generate electrons.
In 1897, using fully-evacuated ("vacuum") tubes, J.J. Thomson established that the "rays" were better described as particles and determined their mass and charge.
Initially naming the particles as "corpuscles", Thomson changed the name to "electrons".
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What did integrated circuits replaced?
The integrated circuit replaced vacuum tubes in electronic devices. This improved electronic devices because the two main problems with vacuum tubes were: 1. Heat generation/ power consumption and 2. Fragility
Where did the electrons from cathode ray come from?
In a cathode ray tube (CRT), the particles, which are electrons, originate at the heated cathode, becoming the so-called cathode rays. The electrons stream off the cathode and rush over to the anode.
Why did transistors eventually replaced the vacuum tubes?
The main advantage is that transistors use less power. A typical small vacuum tube uses about 1.8 watts to heat its cathode, plus 3-5 watts to supply the main current to the anode. By contrast a computer motherboard might take 10-20 watts to power several million transistors.
Why is the cathode-ray tube in figure 4 connected to a vacuum pump?
A Cathode-ray tube is a vacuum that is used to get the air out. Cathode rays (electrons) cannot penetrate through any significant amount of air.
Why is ce configuration employed in transistors?
for the same reason cs is employed with FETs and cc is employed with vacuum tubes: high voltage gain & high current gain.
The emission of electrons in high-vacuum tubes is caused by?
The heating by the filament causes the electrons to "boil off". Edison noted this phenomena and it was later picked up by Fleming who used a "grid" which could control the flow of the electrons by introducting a repelling field between the Cathode (heated element that emitted the electrons) and the anode that attracted the free electrons, thus the "Fleming Valve" was invented (the vacuum tube.
Reasons for no air in vacuum tubes?
Vacuum tubes perform their various functions on the principle of streaming electrons: that is electrons able to fly across space from one electrode to another. If there is air in the tube then this is a barrier to the electron's flight and the tube cannot function.
How does a vacuum tube work?
contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—from the cathode to the anode. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grids.[5]
How many vacuum tubes are in the Univac I computer?
It used 5200 vacuum tubes.
Do all vacuum tubes light up?
No, there are some cold cathode vacuum tubes. These do not light.
What was inside the first computers that would get very hot?
The heaters of the vacuum tubes glowed red hot to make the cathodes emit electrons.
Where is a good place near Seattle where you can buy old vacuum tubes?
This would depend on the type of vacuum tubes needed. Any car part store will carry vacuum tubes for a car, general stores carry vacuum tubes for household vacuums, and AC part stores will carry vacuum tubes for the AC/Heating system of a house.?æ
Where was vacuum tube was made?
who made the vacuum tubes
Does beta radiation results in the emission of electrons?
In beta radiation, an emission of electrons can occur due to beta decay. A neutron can disintegrate into protons and electrons.
How many vacuum tubes in first generation computer?
ENIAC was the first digital general purpose computer, built in 1946, and with 17,468 vacuum tubes. The Illiac I, the first computer built and owned by a US educational institution, had 2800 vacuum tubes. The IBM 604 had about 2000 vacuum tubes.
What technology replaced vacuum tubes in the second generation?
Vacuum tubes were first replaced by transistors, and later by integrated circuits.
Why modern devices use integrated circuit instead of vacuum tubes?
Modern devices use integrated circuits instead of vacuum tubes because integrated circuits occupy less space than vacuum tubes, are more efficient, consumes less energy and are more reliable than vacuum tubes.
