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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
How can they be made to leave the metal surface? (State any two ways)
In a cathode ray tube state:
(i) the purpose of covering cathode by thorium and carbon.
(ii) the purpose of the fluorescent screen.
(iii) how is it possible to increase the rate of emission of electrons.
Give the relative ionizing power of α, β and γ radiations.
A radioactive source emits three types of radiations.
Name the radiation which has the highest ionizing power.
State two properties that a substance should possess when used as a thermionic emitter.
How is a cathode ray tube used to convert an electrical signal into a visual signal?
Are all the radiations viz. α, β and γ emitted in a single radioactive decay?
Justify with reason, whether the following nuclear reactions are allowed or not.
\[\ce{^A_Z X -> ^A_{Z - 2}X + ^4_{2}He}\]
State one use of radio-isotopes.
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be ______.
