Convert 2 Gy to Sv for gamma radiation (QF ≈ 1).

• A. 1 Sv
• B. 2 Sv
• C. 4 Sv
• D. 20 Sv

Answer: (B)

The key idea is how absorbed dose (gray) and equivalent dose (sievert) relate through the radiation quality factor (QF). The gray measures energy deposited per kilogram, while the sievert adjusts that energy to reflect biological damage using QF. For gamma radiation, QF is about 1, so the adjustment is essentially none. Multiply the absorbed dose by QF to get the equivalent dose: 2 Gy × 1 ≈ 2 Sv. That’s why the correct result is 2 sieverts.

If the radiation had a higher QF, the same 2 Gy would yield a larger sievert value (for example, alpha particles with a much higher QF would give a much bigger Sv). The other numbers would require different QFs (not gamma), which is why they don’t apply here.