If the wavelength of a sound wave increases and the frequency of the sound wave does not change, the speed of the wave will increase.
Ans: D
Explanation
The sound wave speed is given by E=fλ, where f indicates its frequency and λ indicates its wavelength.
From the equation, it is evident that the sound speed is proportional to both frequency and wavelength.
Here, as wavelength increases, wave speed increases provided there is no change in frequency.