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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
- The electric potential at the surface of an atomic nucleus (z=50) of radius
- A plane wave of wavelength 6250Å is incident normally on a slit of width 2×10⁻² cm.
- In a circuit, 5% of total current passes through a galvanometer. If resistance
- In India, electricity is supplied for domestic use at 200V. It is supplied at 110 V
- A particle starting from the origin (0, 0) moves in a straight line in the (x, y) plane
Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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