jee-main 2005 Q72

jee-main · India Not Maths
The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to $\frac{I}{8}$. The thickness of lead which will reduce the intensity to $\frac{I}{2}$ will be
(1) 6 mm
(2) 9 mm
(3) 18 mm
(4) 12 mm
The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to $\frac{I}{8}$. The thickness of lead which will reduce the intensity to $\frac{I}{2}$ will be\\
(1) 6 mm\\
(2) 9 mm\\
(3) 18 mm\\
(4) 12 mm