Sound waves of wavelength `alpha` travelling in a medium with a speed of v m `s^(-1)` enter into another medium where its speed is 2v m `s^(-1)`. Wavelength of sound waves in the second medium is

Options

A. `lambda`
B. `(lambda)/(2)`
C. `2 lambda`
D. `4 lambda`

Answer

C

Explanation

Frequency of wave will remain same in both the media.
In 1st medium, `v = (upsilon)/(lambda)" "…(i)`
In 2nd medium, `v = (2 upsilon)/(lambda')" "…(ii)`
From (i) and (ii)
`(upsilon)/(lambda) = (2upsilon)/(lambda')`
or `lambda' = 2 lambda`
The correct option is (c).