Question

x-rays are produced in an X-ray tube by electrons asselerated through an electric potential difference fo 50.0 kV. An electron makes three collisions in the target coming to rest and loses half its remaining kinetic energy in each of the first two collisions. Determine the wavelenght of the resulting photons. (Neglecting the recoil of the heavey target atoms).

Answer 1

Correct Answer - D
`DeltaE_1 = 50% of 50 keV = 23keV`
`:. Lambda_1 = (12375)/(25xx10^3) = 0.495 Å`
= 49.5 pm
`DeltaE_2 = 50% of 25 keV`
=12.5 keV
`:. Lambda_2 = (12375)/(12.5xx10^3) = 0.99 Å`
= 99 pm.