How does added filtration affect the average energy of an X-ray beam?

How does added filtration affect the average energy of an X-ray beam?

• A. It increases
• B. It decreases
• C. It remains unchanged
• D. It becomes unpredictable

Answer: (A)

Adding filtration removes the softer, low-energy photons from the beam. Those low-energy photons are more easily absorbed and don’t contribute much to penetrating power. When they’re filtered out, the remaining photons are comparatively higher energy, so the spectrum becomes harder. This shift increases the average energy of the beam, even though the total number of photons (intensity) goes down.

Adding filtration removes the softer, low-energy photons from the beam. Those low-energy photons are more easily absorbed and don’t contribute much to penetrating power. When they’re filtered out, the remaining photons are comparatively higher energy, so the spectrum becomes harder. This shift increases the average energy of the beam, even though the total number of photons (intensity) goes down.