What unit is used to measure effective dose in radiation?

• A. Gray (Gy)
• B. Sievert (Sv)
• C. Rem (Roentgen Equivalent Man)
• D. Curie (Ci)

Answer: (B)

The unit used to measure effective dose in radiation is the Sievert (Sv). The effective dose quantifies the biological effect of radiation on human tissue, accounting for both the type of radiation and the sensitivity of different tissues and organs to radiation. The Sievert provides a standardized way to compare the risk of radiation exposure across various types of radiation and different exposure scenarios.

Other units mentioned in the question are used for different measurements in radiation physics. The Gray (Gy) is a unit that measures absorbed dose, which is the amount of energy deposited by ionizing radiation in a material but does not consider biological effects. The Rem (Roentgen Equivalent Man) is an older unit, similar to the Sievert, that has been largely replaced by the SI unit of Sievert but is still sometimes encountered in practice. The Curie (Ci) measures the activity of a radioactive substance, indicating how many disintegrations occur per second, but it does not relate directly to the dose received by biological tissue. Therefore, in the context of effective dose measurement, Sievert is the most appropriate and widely recognized unit.