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प्रश्न
Why are materials of low work function preferred as thermionic cathode materials?
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उत्तर
By using materials of low work functions, the emission of electrons from such a surface takes place at relatively low temperature (at 1700°C in instead of 2500°C approximately).
संबंधित प्रश्न
What are free electrons?
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Give one example of isobars.
A radioactive source emits three types of radiations.
Name the radiation which has the highest ionizing power.
How is a cathode ray beam affected while passing through a magnetic field?
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Name a common device where a hot cathode ray tube is used.
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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
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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 ______.
