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A radioactive substance has a half-life of four months. Three-fourth of substance will decay in
Options
(a) 3 months
(b) 4 months
(c) 8 months
(d) 12 months
Correct Answer:
8 months
Explanation:
Substance left undecayed N = N₀ – (3 / 4) N₀ = (1 /4) N₀
N / N₀ = (1 / 2)ⁿ
where n = number of half lives
.·. 1 / 4 = (1 / 2)ⁿ (or), n = 2 n = t / T₁/₂ t = nT₁/₂ = 2 × 4 = 8 months.
Related Questions: - Two point charge +9e and +e are at 16 cm away from each other.
- A ship of mass 3 x 10⁷ kg initially at rest is pulled by a force of 5 x 10⁴ N through
- If the radioactive dacay constant of radium is 1.07 x 10⁻⁴ year⁻¹, then its half-life
- A circular disc X of radius R is made from an iron plate of thickness t and another disc
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Topics: Radioactivity
(83)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Two point charge +9e and +e are at 16 cm away from each other.
- A ship of mass 3 x 10⁷ kg initially at rest is pulled by a force of 5 x 10⁴ N through
- If the radioactive dacay constant of radium is 1.07 x 10⁻⁴ year⁻¹, then its half-life
- A circular disc X of radius R is made from an iron plate of thickness t and another disc
- The moment of inertia of a thin circular disc about an axis passing through its centre
Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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