1.Length is one of the four factors on which the wave frequency depends. So if the length of the string changes then there will be a change in the vibration of string. So in this case if the lengths are different then the wave frequency of both will be different.
2. Wave speed will be the same as it depends on tension and linear density of it.
3. Wavelength itself is find out by the length of string so it depends on length and it will vary with the lengths of strings.
