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Half-lives of two radioactive substances...

Half-lives of two radioactive substances `A` and `B` are respectively `20` minutes and `40` minutes. Initially, he sample of `A` and `B` have equal number of nuclei. After `80` minutes the ratio of the remaining number of `A` and `B` nuclei is :

A

`1:4`

B

`1:2`

C

`1:1`

D

`1:8`

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AAKASH INSTITUTE-NUCLEI-Assignment Section A Objective (One option is correct )
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  2. Alpha rays emitted from a radioactive substance are

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  3. In the given reaction .z X^A rarr .(z+1)Y^A rarr .(z-1) K^(A - 4) ra...

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  4. The radioactivity of a certain radioactive element drops to 1//64 of i...

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  5. If T is the half-life of a radioactive material, then the fraction tha...

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  6. The half-life of a radioactive element which has only (1)/(32) of its ...

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  7. The life-life of Bi^210 is 5 days. What time is taken by (7//8)^th par...

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  8. A radioactive nucleus undergoes a series of decay according to the sch...

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  9. Half-life of radioactive element depend upon

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  10. The half-life period of a radioactive substance is 5 min. The amount o...

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  11. Half-lives of two radioactive substances A and B are respectively 20 m...

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  12. Half-life of a radioacitve element is 10 days. The time during which q...

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  13. An element A decays into element C by a two-step process : A rarr B ...

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  14. During mean life of a radioactive element, the fraction that disintegr...

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  15. The half-life of a radioactive substance against alpha-decay is 1.2 xx...

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  16. The activity of a sample of a radioactive meterial is A1 , at time t1 ...

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  17. A radioactive substance has an average life of 5 hours. In a time of 5...

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  18. A sample of radioactive element has a mass of 10 g at an instant t=0. ...

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  19. The half-life of a sample of a radioactive substance is 1 hour. If 8 x...

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  20. A nucleus of mass 220 amu in the free state decays to emit an alpha-pa...

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