Electrons with energy `80 keV` are incident on the tungsten target of an X - rays tube , k- shell electrons of tungsten have `72.5 keV` energy X- rays emitted by the tube contain only

Options

A. a continous X-ray spectrum (Bremsstrahlung) with a minimum wavelength of `~0.155 Å`
B. a continous X-ray spectrum (Bremsstrahlung) with all wavelengths
C. the characteristic X-ray spectrum of tungsten
D. a continous X-ray spectrum (Bremsstrahlung) with a minimum wavelength of `~0.155 Å` and the characteristic X-ray spectrum of tungsten

Answer

D

Explanation

`lambda_(min)=1242/(80xx10^(3))=15.5xx10^(-3) nm=0.155 Å`
Since `80gt72.5`, K-shell electron is knocked out, hence characteristic spectrum