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प्रश्न
State two characteristics of the substance used as thermionic emitter.
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उत्तर
(i) The substance must have high melting point.
(ii) The work function of the substance should be low so that electrons may be emitted even at low temperature.
संबंधित प्रश्न
Answer the following questions based on a hot cathode ray tube.
State the approximate voltage used to heat the filament
Radioactive substances were found to give off three types of rays. Name them. How do they
(a) React to the magnetic field?
(b) React to the electric field?
(c) Act when different thickness of lead sheets is placed in their path?
A radioactive substance is oxidized. What changes would you expect to take place in the nature of radioactivity? Explain your answer.
How is a cathode ray tube used to convert an electrical signal into a visual signal?
Name the Different Radiations Which Are Emitted by the Radioactive Substances.
Are all the radiations mentioned by you, emitted in a single radioactive decay?
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 ______.
A radioctive sample decays `7/8` times its original quantity in 15 minutes. The half-life of the sample is ______.
Calculate the time interval between 33% decay and 67% decay if half-life of a substance is 20 minutes.
Assertion (A): Hydrogen atom consists of only one electron but its emission spectrum has may lines.
Reason (R): Only Lyman series is found in the absorption spectrum of hydrogen atom whereas in the emission spectrum, all the series are found.
Which decay process involves the emission of a particle with a comparatively large mass and a positive charge?
