For normal mammography, X-ray tube with a nominal focal size of-mm is used?: (A) 0.2-0.25, (B) 0.3-0.35, (C) 0.4-0.45, (D) 0.45-0.50
Answer is B. Ans BIn general smaller the focal spot sharper the image Routinely focal spot size 0.3x0.3mm while magnification technique small focus of 0.1x0.1mm is used.