What is the unit for absorbed dose?

What is the unit for absorbed dose?

• A. Joules/kilogram (J/kg)
• B. Coulombs/kilogram (C/kg)
• C. D x radiation weighting factor (Wr)
• D. D x Wr x tissue weighting factor (Wt)

Answer: (A)

Absorbed dose is how much energy from ionizing radiation is deposited in a mass of tissue per unit mass. That definition anchors its unit: joules per kilogram, or gray (Gy), with 1 Gy = 1 J/kg. This directly reflects energy deposition per mass, which is why J/kg is the correct unit. Coulombs per kilogram would measure charge per mass, not energy deposited, so it doesn't represent absorbed dose. The other expressions involve weighting factors used to compute dose equivalent or effective dose, which are related concepts but describe different quantities; they still relate to energy per mass, but the question asks for the unit of absorbed dose itself, which remains J/kg (Gy).

Absorbed dose is how much energy from ionizing radiation is deposited in a mass of tissue per unit mass. That definition anchors its unit: joules per kilogram, or gray (Gy), with 1 Gy = 1 J/kg. This directly reflects energy deposition per mass, which is why J/kg is the correct unit.

Coulombs per kilogram would measure charge per mass, not energy deposited, so it doesn't represent absorbed dose. The other expressions involve weighting factors used to compute dose equivalent or effective dose, which are related concepts but describe different quantities; they still relate to energy per mass, but the question asks for the unit of absorbed dose itself, which remains J/kg (Gy).