If the intensity of radiation at 72 inches is 225 mR, what is the intensity if the SID is decreased to 40 inches?

Question

Quizplus · Accepted Answer

The intensity of radiation is inversely proportional to the square of the distance (Inverse Square Law). If the distance is decreased from 72 inches to 40 inches, the intensity increases. Calculating using the formula: (I1/I2) = (D2^2/D1^2), we get (225/I2) = (40^2/72^2), solving for I2 gives approximately 729 mR.

If the Intensity of Radiation at 72 Inches Is 225