NEET Physics Nuclei Questions Solved


From a newly formed radioactive substance (Half life 2 hours), the intensity of radiation is 64 times the permissible safe level. The minimum time after which work can be done safely from this source is

(a) 6 hours            (b) 12 hours
(c) 24 hours          (d) 128 hours

(b) NN0=12n164=126=12nn=6

After 6 half lives intensity emitted will be safe.
 Total time taken = 6×2=12 hrs

Difficulty Level:

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