The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to I/8. The thickness of lead, which will reduce the intensity to I/2 will be
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The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to I/8. The thickness of lead, which will reduce the intensity to I/2 will be

G1 Physics · Accepted Answer

Intensity attenuation is exponential: I = I₀ exp(−μx). Given 36 mm reduces intensity to I₀/8 = I₀/2³, 36 mm corresponds to three half-value layers. Therefore one half-value layer is 36/3 = 12 mm. Correct answer: D.