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प्रश्न
Why do Free electrons not leave the metal surface on their own
उत्तर
Free electrons cannot leave the metal surface on their own because they do not have sufficient kinetic energy.
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संबंधित प्रश्न
Answer the following questions based on a hot cathode ray tube.
State the approximate voltage used to heat the filament
When is said to be the nucleus unstable?
A radioactive source emits three types of radiations. Name them.
(i) Name the radiations which are charged.
(ii) Name the radiations which are most penetrating.
(iii) Name the radiations which travel with the speed of light.
(iv) Name the radiations which have the largest mass.
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?
State two properties that a substance should possess when used as a thermionic emitter.
In a cathode ray tube state the purpose of covering cathode by thorium and carbon.
Are all the radiations viz. α, β and γ emitted in a single radioactive decay?
A certain nucleus has a mass number 20 and atomic number 9. Find the number of neutrons and protons present in it.
Mention four properties of Becquerel rays.
