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Question
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?
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Solution
A radioactive source emits three types of radiations. These are a
radiations, β radiations and γ radiations.
(i) α particles are heavy in mass and have positive charge so they are less deflected by magnetic field. β particles are Iighter in mass and have negative charge so they are deflected mo re by magnetic field in opposite direction to a particle's deflection. γ radiations are charge less and mass less so they are not deflected by magnetic field.
(ii) a particles are heavy in mass and have positive charge so they are less deflected by electric field towards negative plate. β particles are Iighter in mass and have negative charge so they are deflected mo re by electric field towards positive plate. γ radiations are charge less and mass less so they are not deflected by electric field.
(iii) The penetrating power of a particle is least. They can't penetrate lead sheet very much. Penetrating power of β particles is less but 100 times mo re than that of a particle. So, it will penetrate lead sheet more than a particles. γ radiations have maximum penetration power. They are 100 times more penetrating than β particles. So, γ radiations wouId penetrate in lead sheet by larqest amount.
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