The Department of Chemistry at the University of Illinois

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Cathode Ray Tube

close-up, cathode ray tube showing electron beam

How does a cathode ray tube work? Roll the mouse over the labels see a description of that part.

photo, green balloon The cathode ray tube is a sealed glass tube from which most of the air has been removed. The tube won't work if it is full of air. In order to induce the metal cathode to emit electrons, a strong electrical current is required. So a cathode ray tube will not work without a power source. A thin piece of metal coated with a material that emits light when struck by electrons is sealed inside the tube to detect the path of the electronsThe anode is the metal electrode towards which the electrons travel. The anode is the p ositive electrode.This piece of glass connects the cathode ray tube to the stand.A wooden stand supports the cathode ray tubeAn aligator clip connects the metal electrode to the power source The cathode is metal electrode from which the electrons originate. The cathode is the negative electrode.

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cathode ray tube

The path of the electron beam is curved in a magnetic field.


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Chemistry at Illinois University of Illinois at Urbana-Champaign