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Thermionic Emission and Radioactivity
i) Why is a cathode ray tube evacuated to a low pressure?
ii) What happens if the negative potential is changed on the grid?
i) The cathode ray tube is evacuated to a low pressure so that the electrons may move without being obstructed by air molecules.
ii) The variation of the negative potential on the grid affects the number of electrons reaching the the anode and striking the screen changed which changes the brightness of pattern on the screen.
What is thermionic emission?
The emission of electrons from a metal surface when heat or thermal energy is imparted to it, is called thermionic emission.
Name the unit in which the work function of a metal is expressed?
The unit of work functions is, eV (electron volt); 1 eV = 1.6 x 10-11 J
Complete the diagram as given above by drawing the deflection of radioactive radiation in an electric field.
Hot Cathode Ray Tube - Deflection of radioactive radiations in an electric field.
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Mock Test Series
Mock Test Series