Competitive Exams: Current Affairs 2011: Sievert


The sievert (symbol: Sv) is the International System of Units (SI) SI derived unit of dose equivalent radiation.

It attempts to quantitatively evaluate the biological effects of ionizing radiation as opposed to the physical aspects, which are characterised by the absorbed dose, measured in gray. It is named after Rolf Maximilian

Sievert, a Swedish medical physicist renowned for work on radiation dosage measurement and research into the biological effects of radiation.


The gray (symbol: Gy) is the SI unit of absorbed radiation dose of ionizing radiation (for example, X-rays), and is defined as the absorption of one joule of ionizing radiation by one kilogram of matter (usually human tissue). Named after the British physicist Louis Harold Gray, the SI unit replaces the traditional cgs unit, the rad (equivalent to 0.01 Gy). Curie The curie (symbol Ci) is a unit of radioactivity. It is named after Marie and Pierre Curie. Note: Radioactivity was first discovered in 1896 by the French scientist Henri Becquerel.

Courtesy: The Hindu and Times of India