If the radiation weighting factor Wr is 1, the equivalent dose equals the absorbed dose.

• A. True
• B. False
• C. Depends on tissue
• D. Depends on exposure time

Answer: (A)

The main idea is that equivalent dose adjusts the absorbed dose by a factor that reflects how biologically damaging the radiation is. This factor is the radiation weighting factor, Wr. If Wr is 1, there’s no extra scaling applied, so the equivalent dose for that radiation type and tissue is numerically the same as the absorbed dose. In other words, 1 Gy of radiation with Wr = 1 contributes 1 Sv of equivalent dose for that tissue. This applies to types like X-rays, gamma rays, and beta particles, which have Wr = 1. If you had a radiation type with Wr greater than 1 (such as alpha particles) or you were combining multiple radiation types, the equivalent dose would differ from the absorbed dose accordingly.