Question

name the type of x rays in which wavelength depends on : voltage applied across the x rays tube and material of the target

Answer 1

As you know there are two types of x - rays .
characteristics x - rays : wavelength of characteristics x-rays is independent of accepting potential but depends on target atom.

continuous x- rays : wavelength of continuous x-rays produced depends on accelerating potential and independent of target atom.

now you can solve it easily !
wavelength of characteristics x - rays depends on voltage applied across the x - ray tube.
and wavelength of continuous x - rays depends on target material .