<prompt> One gray equals10 RAD100 RAD1000 RAD10000RAD  <response>: SI unit of radiation absorbed dose is GRAY 1 Gy 1JKgAbsorbed dose is the energy absorbed as ionization or excitation per unit mass of the material irradiated.The concept of absorbed dose applies to all kinds of ionizing radiation direct and indirect and to any material.Before 1980 the international dose of absorbed dose is RAD1 Gy100 rad 1rad1cGy10 mGyRef: Farr;s Physics for Medical Imaging, 2nd Edition, Page No 17 