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The half life of radium is about 1600 year. Of 100 gram of radium existing now, 25g will remain unchanged after
Options
(a) 4800 year
(b) 6400 year
(c) 2400 year
(d) 3200 year
Correct Answer:
3200 year
Explanation:
100 gram at beginning, I = 0
25 gram remains undecayed.
N / N₀ = (1 / 2)ⁿ ⇒ 25 / 100 = (1 / 2)ⁿ
⇒ 1 / 4 = (1 / 2)ⁿ
Therefore, n = 2
Time = n × T
= 2 × 1600
= 3200 years.
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Subject: Physics
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Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- The distance travelled by a particle starting from rest and moving
- If an A.C. mains supply is given to be 220 V, what would be the average e.m.f.
- A jar is filled with two non-mixing liquids 1 and 2 having densities
- The threshold frequency for a metallic surface corresponds to an energy of 6.2 eV,
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Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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