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प्रश्न
An electrons emitter must have how much work function and melting point.
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उत्तर
An electron emitter must have low work function and high melting point.
संबंधित प्रश्न
State three factors on which the rate of emission of electrons from a metal surface depends
Why do Free electrons not leave the metal surface on their own
Why is a cathode ray tube evacuated to a low pressure?
What are the uses of radioactive isotopes in following?
(a) Medical field,
(b) Agriculture,
(c) Industries?
Name a common device where a hot cathode ray tube is used.
Name the Different Radiations Which Are Emitted by the Radioactive Substances.
Are all the radiations mentioned by you, emitted in a single radioactive decay?
Which of the following statements is/are correct?
- α particles are photons
- Penetrating power of γ radiation is very low
- Ionization power is maximum for α rays
- Penetrating power of γ radiation is very high
The count rate of activity of a radioactive sample of a very large population decreased from 1024 to 128 in 3 minutes. Then the rate of disintegration at the end of 5 minutes is ______.
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)
