If wavelength of a sound wave in a medium is reduced by 50% , then the percentage change in its frequency is

Options

A. 0.5
B. 1
C. 0.25
D. 0.75

Answer

B

Explanation

`n = (v)/(lamda) and n' = (v)/(lamda')`
As `lamda' = lamda - (50 lamda)/(100) = lamda (0.5) " " :. (lamda')/(lamda) = 0.5`
`(n')/(n) = (lamda)/(lamda') = (1)/(0.5) = (10)/(5) = 2`
`(n')/(n) -1 = 2 -1 " " :. (n' -n)/(n) = 1`
`:. N - n % = 100% n`