(b) The minimum wavelength of X-rays produced by 30 kV electrons.
(a) Hint:E=hv
Step: Find the maximum frequency AsE=hv⇒v=Eh=1.6×10−19×30×1036.626×10−34=7.24×1018Hz. (b) Hint:c=νλ Step: Find the minimum wavelength Asc=νλ⇒λ=cν=3×1087.24×1018=4.14×10−11m=0.0414m.