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A radioactive source of halflife 2 h emi...

A radioactive source of halflife 2 h emits radiation of intensity which is 64 times the permissible safe level. The minimum time in hours after which it would be possible to work safely with the source is:

A

`6 h`

B

`12 h`

C

`24 h`

D

`128 h`

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The correct Answer is:
B
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HC VERMA-THE NUCLEOUS-Objective 1
  1. The mass of a neutral carbon atom in ground state is

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  2. The mass number of a nucleus is equal to

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  3. As compared to ^12C atom, ^14C atoms has

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  4. The mass number of a nucleus is equal to

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  5. The graph of 1n (R/R0) versus 1n A (R = radius of a nucleus and A = it...

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  6. Let Fpp, Fpn and Fnn denote the magnitudes of the nuclear force by a p...

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  7. Let Fpp, Fpn and Fnn denote the magnitudes of the nuclear force by a p...

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  8. Two protons are kept at a separation of 10 nm. Let Fn and Fe be the nu...

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  9. As the mass number A increases, the binding energy per nucleon in a nu...

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  10. Which of the following is a wrong description of binding energy of a n...

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  11. In one average-life,

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  12. In a radioactive decay, neither the atomic number nor the mass number ...

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  13. During negative beta-decay

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  14. A radioactive source of halflife 2 h emits radiation of intensity whic...

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  15. The decay constant of a radioactive sample is lambda. The half-life an...

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  16. An alpha particle is bombarded on ^14N. As a result, a 17O nucleus is ...

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  17. Ten grams of ^57 Co kept in an open container beta-decays with a half-...

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  18. Free ^238 U nuclei kept in a train emit alpha particles. When the trai...

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  19. During a nuclear fission reaction,

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