Thickness of lead apron is-

Ans. is 'c' i.e. 0.5 mm "It is recommended that for general purpose radiography the minimal thickness of lead equivalent in the protective apparel should be 0.5mm." - Textbook of Radiology Physics p. 39* Lead apron of 0.5mm thickness reduce intensity of scattered X-rays by over 90%.Lead apron* A lead apron or leaded apron is a type of protective clothing that acts as a radiation shield. It is constructed of a thin rubber exterior and an interior of lead in the shape of a hospital apron. The purpose of the lead apron is to reduce exposure of a hospital patient to x-rays to vital organs that are potentially exposed to ionizing radiation during medical imaging that uses x-rays (radiography, fluoroscopy, computed tomography).* Lead can effectively attenuate certain kinds of radiation because of its high density and high atomic number; principally, it is effective at stopping gamma rays and x-rays.* Protection of the reproductive organs with a lead apron is considered important.* The thyroid gland is especially vulnerable to x-ray exposure. Care should be taken to place a lead apron over the thyroid gland before taking dental radiographs.