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प्रश्न
What are the types of emission?
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उत्तर
There are four types of emissions:
(i) Thermionic emission. (ii) Photoelectric emission.
(iii) Field emission. (iv) Secondary emission.
संबंधित प्रश्न
State the energy conversion taking place in a cathode ray tube
Represent the change in the nucleus of a radioactive element when a β particle is emitted.
Why is a cathode ray tube evacuated to a low pressure?
State the penetrating range of α, β and γ radiations.
What happens to the mass number of an element when (i) an α -particle, (ii) a β -particle, and (iii) γ -radiation is emitted?
In the following fig. shows a radioactive source S in a thick lead container. The radiations pass through an electric field between the plates P and Q. Complete the diagram to show the paths of α , β and γ radiations.
Why is the source S placed in a thick lead container?
Name two radioactive substances.
What are cathode rays? Why are they called ‘cathode rays’? Name a material which exhibits fluorescence when cathode rays fall on it.
Two radioactive nuclei are represented by xAp and yAq and when p and q are mass numbers and x, y are the atomic number. How can the products be represented, i .e., what are the new values of p, q. x and y after the emission of an α-particle and a β-particle from A and B respectively.
Assertion (A): The force of repulsion between atomic nucleus and α-particle varies with distance according to inverse square law.
Reason (R): Rutherford did α-particles scattering experiment.
