To solve this problem it is necessary to express the term of the wavelength of continuous x-rays according to the Planck constant, the speed of light, the charge of the electron and the voltage. This definition is expressed mathematically as
Here,
h is Planck's constant
c is speed of light
e is charge of electron
V is the potential to which the electrons are accelerated.
From this definition we can see that the wavelength is independent of the mass of the target material. Therefore the wavelength will remain the same.