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प्रश्न
What is thermionic emission?
उत्तर
The emission of electrons from a metal surface when heat energy is imparted to it is called thermionic emission
संबंधित प्रश्न
Give the relative ionizing power of α, β and γ radiations.
An element P disintegrates by α - -emission and the new element suffers two further disintegrations, both by β -emission, to form an element Q. Explain the fact that P and Q are the isotopes.
How is a cathode ray beam affected while passing through a magnetic field?
Name the Different Radiations Which Are Emitted by the Radioactive Substances.
Are all the radiations mentioned by you, emitted in a single radioactive decay?
From α, β and γ-rays, name the one which travels with the speed of light?
Explain, why radium paint, consisting of zinc sulphide and a trace of radium salt, glows in the dark?
In U238 ore containing Uranium the ratio of U234 to Pb206 nuclei is 3. Assuming that all the lead present in the ore is final stable product of U238. Half life of U238 to be 4.5 × 109 years and the age of ore is ______ × 109 years. (in 109 years)
The mean lives of a radioactive substance are 1620 and 405 years for β-emission and β-emission respectively. The time after which three fourth of a sample will decay if it is decaying both by β-emission and β-emission simultaneously will be ______ years.
(Take ln 2 = 0.693)
