Question

Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K-shell electrons of tungsten have 72.5 keV energy. X-rays emitted by the tube contain only: (IIT JEE 2000)

• A. a continuous X-ray spectrum (|Bremsstrahlung) with minimum wavelength of $\approx$ 0.155 Å
• B. a continuous X-ray spectrum (Bremsstrahlung) with all wavelengths
• C. the characteristic X-ray spectrum of tungsten
• D. a continuous X-ray spectrum (Bremsstrahlung) with minimum wavelength of $\approx$ 0.155 Å and the characteristic X-ray spectrum of tungsten.

Answer 1

The correct option is D

a continuous X-ray spectrum (Bremsstrahlung) with minimum wavelength of $\approx$ 0.155 Å and the characteristic X-ray spectrum of tungsten.

Since the energy of an electron is more than the energy required to knock an electron out from the K-shell, we will have both continuous and the characteristic spectrum here.