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 - Physics MCQ AIEEE 2026 | ExamTest.live

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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:

Solution & Step-by-step Explanation

Intensity follows the law I = I_{0} e^{- μx} or I = I_{0} (1/2)^{x / x_{1/2}} where x_{1/2} is the half-value thickness.Given I = I_{0} /8 when x = 36 mm . I_{0} /8 = I_{0} (1/2)^{36/ x_{1/2}} (1/2)^{3} = (1/2)^{36/ x_{1/2}} ⟹ 3 = 36/ x_{1/2} ⟹ x_{1/2} = 12 mm The thickness to reduce intensity to I /2 is exactly the half-value thickness.So, x = 12 mm .

Try it yourself before checking the explanation above.

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:

6 mm

9 mm

18 mm

12 mm

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