In bremsstrahlung, the photon energy is determined by which statement?

• A. Yes
• B. No
• C. Only for certain materials
• D. Cannot be determined

Answer: (A)

Photon energy in bremsstrahlung is determined by the energy carried away from the incident electron as it is decelerated by the nucleus. The electron’s available kinetic energy sets the upper limit for the emitted photon’s energy, and the actual photon energy can take any value from near zero up to that maximum depending on how much energy is radiated in that interaction. In other words, the spectrum is continuous from 0 to the incident electron energy, with the nucleus’ charge mainly affecting how likely radiation is to occur rather than fixing the energy range. That’s why the statement that the photon energy is determined by the incident electron energy is the best choice. The other options conflict with energy conservation or misstate the role of the material, since the maximum photon energy does not depend on the material, and it is not undeterminable.