The intensity of sound from a radio at a distance of $2$ metres from its speaker is $1 \times {10^{ - 2}}\mu \;W/{m^2}.$ The intensity at a distance of $10$ meters would be
A$0.2 \times {10^{ - 2}}\mu \;W/{m^2}$
B$1 \times {10^{ - 2}}\mu \;W/{m^2}$
C$4 \times {10^{ - 4}}\mu \;W/{m^2}$
D$5 \times {10^{ - 2}}\mu \;W/{m^2}$
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C$4 \times {10^{ - 4}}\mu \;W/{m^2}$
c (c) $I \propto \frac{1}{{{r^2}}} \Rightarrow \frac{{{I_2}}}{{{I_1}}} = \frac{{r_1^2}}{{r_2^2}}$
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