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प्रश्न
In a cathode ray tube state the purpose of covering cathode by thorium and carbon.
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उत्तर
Purpose of covering cathode by thorium and carbon is to reduce its work function, decrease its melting point.
संबंधित प्रश्न
How can they be made to leave the metal surface? (State any two ways)
What are isobars?
In following fig. shows a mixed source S of alpha and beta particles in a thick lead container. The particles pass through a magnetic field in a direction perpendicular to the plane of paper (inwards as shown by x). State and show in the diagram how the particles get affected.
What is nucleus of an atom? Compare its size with that of the atom. Name its constitutents. How is the number of these constituents determined by the atomic number its atomic model.
Name two radioactive substances.
A certain nucleus has a mass number 20 and atomic number 9. Find the number of neutrons and protons present in it.
A radioactive nucleus \[\ce{^A_ZX}\] undergoes spontaneous decay in the sequence \[\ce{^A_ZX -> _{Z-1 }B -> _{Z-3}C -> _{Z-2}D }\], where Z is the atomic number of element X. The possible decay particles in the sequence are ______.
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be ______.
A radioctive sample decays `7/8` times its original quantity in 15 minutes. The half-life of the sample is ______.
In the following atoms, which one is a radioisotope? Give one use of this isotope.
O16, C14, N14, He4
