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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.
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Topics: Radioactivity
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Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- The time of reverberation of a room A is one second. What will be the time (in seconds)
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- Laser beams are used to measure long distance because
- A thin convex lens of refractive index 1.5 has 20 cm focal length in air. If the lens
- A circular road of radius 1000m has banking angle 45°.The maximum safe speed of a car
Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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