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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
(83)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- IF A⃗ and B⃗ are two vectors and θ is the angle between them
- The equation of state for 5 g of oxygen at a pressure P and temperature T,
- The unit of permitivity of free space, ε₀ is
- A milli ammeter of range 10 mA has a coil of resistance 1 ohm
- Photons with energy 5eV are incident on a cathode C in a photoelectric cell.
Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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