Sound waves of wavelength λ travelling in a medium with a speed of v m/s enter into another medium where its speed is 2v m/s. The wavelength of sound waves in the second medium is
Sound waves of wavelength λ travelling in a medium with a speed of v m/s enter into another medium where its speed is 2v m/s. The wavelength of sound waves in the second medium is

a) λ

b) λ/2

c) 2 λ

d) 4 λ

Answer:

The correct answer is c) 2 λ

Explanation:

According to the question, the wavelength of sound waves in the first medium,
                              …….(i)
u represents velocity and v represents the frequency.
The wavelength of sound waves in the second medium,
                          ……..(ii)
With the change in medium, the wave’s frequency remains constant.
                                 ………(iii)
Divide (ii) by (i), we get
or