Which electron energy will produce the largest cutoff wavelength for X-ray production from a nickel (Z = 28) surface?
A)25 keV
B)30 keV
C)35 keV
D)40 keV
E)45 keV

Question

Quizplus · Accepted Answer

The cutoff wavelength for X-ray production is given by λc = hc/E, where h is the Planck's constant, c is the speed of light, and E is the energy of the incident electron. For a nickel surface (Z =28), the maximum cutoff wavelength is obtained for the minimum electron energy that can excite a K-shell electron, which is about 8.3 keV. Therefore, we need to choose the energy that is just above this threshold. Among the given options, only 25 keV satisfies this condition. Hence, the answer is A) 25 keV.

Which Electron Energy Will Produce the Largest Cutoff Wavelength for X-Ray