Answer:
The frequency should increase.
Explanation:
The wavelength of a wave varies inversely to frequency of the wave.
The relation between the frequency and wavelength of a wave is given as:
[tex]f\lambda=v[/tex]
Here, [tex]f\to frequency\\\lambda\to wavelength\\v\to velocity\ of\ wave[/tex]
Therefore, as the wavelength increases then the frequency will decrease.
Similarly, as the wavelength of the wave decreases, then the frequency will increase.
So, the frequency should increase if you decrease the wavelength of a wave.
