One gray of radiation is equal to -: (A) 1 rad, (B) 10 rad, (C) 100 rad, (D) 1000 rad
Answer is C. The activity of radioactive material is the number of nuclear disintegration per unit of time. SI unit of radiation exposure - coulomb per kilogram (1Roentgen = 2.58x10-4 C/kg) absorbed dose - Gray (1 Gray = 100 rad) Dose equivalent - Sieve (Sv) (1 Sv = 100 rems) Park's Textbook of Preventive and Social Medicine, 25th Edition, Pg 804