What is the wavelength of the most energetic X rays emitted from an X-ray tube operated at 40 kV?
A)0.031 nm
B)31 nm
C)1.7 µm
D)25 µm
E)0.75 nm

Question

Quizplus · Accepted Answer

The most energetic X-rays correspond to the shortest wavelength, which can be calculated using the formula λ = 1240/V (nm), where V is the voltage in kV. For 40 kV, λ = 1240/40 = 31 nm, but since the question likely assumes the use of nm and the conversion factor is actually meant to be used for eV to nm (and the question setup implies a direct conversion from kV to pm), the correct calculation should be based on the energy in keV leading to a wavelength in picometers (pm), thus giving a value in nm when divided by 1000. Therefore, the correct answer, considering the context and typical energy to wavelength conversion for X-rays, is 0.031 nm, which corresponds to the highest energy photons that can be emitted by an X-ray tube operating at 40 kV.

What Is the Wavelength of the Most Energetic X Rays