The amplitude of sound is doubled and the frequency is reduced to one fourth. The intensity of sound at the same point will be

Options

A. Increased by a factor of 2
B. Decreased by a factor of 2
C. Decreased by a factor of 4
D. Unchanged

Answer

C

Explanation

Intensity `prop"(Amplitude)"^(2)"(frequency)"^(2) [because I=2pi^(2)a^(2)f^(2)vrho]`
`(I_(1))/(I_(2))=((a)/(2a))^(2)xx((f)/(f//4))^(2)impliesI_(2)=(I_(1))/(4)`.