A source of sound is in the shape of a long narrow cylinder radiating sound waves normal to the axis of the cylinder. Two points P and Q are at perpendicular distances of 9 m and 25 m from the axis. The ratio of the amplitudes of the waves at P and Q is :-

Options

A. `5 : 3`
B. `sqrt(5) : sqrt(3)`
C. `3 : 5`
D. `25 : 9`

Answer

A

Explanation

`IpropA^(2)andI prop(1)/(2)piRL`
`(I_(1))/(I_(2))=(R_(2))/(R_(1))=(A_(1)^(2))/(A_(2)^(2))rArr(A_(1))/(A_(2))=sqrt((R_(2))/(R_(1)))=sqrt((25)/(9))=5:3`.