Question

increasing the source - to - image distance (sid) will result in which of the following?
increased quantity and increased quality of photons
decreased quantity and decreased quality of photons
increased quantity and will have no effect on the quality of photons
decreased quantity and will have no effect on the quality of photons

Explanation:

The intensity of the x - ray beam (quantity of photons) follows the inverse - square law. As the source - to - image distance (SID) increases, the x - ray beam spreads out over a larger area, reducing the number of photons reaching the image receptor. The quality of photons (energy of the x - rays) is determined by factors such as kVp and filtration and is not affected by SID.

Answer:

Decreased quantity and will have no effect on the quality of photons