Apply the 30% rule to a film that was underexposed using 100 mA, .4 second, and 75 kVp. Which answer is correct?

Question

Quizplus · Accepted Answer

The 30% rule states that to compensate for underexposure, increase the mAs by 30%. In this case, the mAs was 100 mA x .4 second = 40 mAs. To increase this by 30%, we multiply by 1.3, which gives us 52 mAs. We can achieve this by either increasing the mA or the exposure time. Choice A increases the mA to 200 mA and decreases the exposure time to .26 second, which gives us 52 mAs (200 mA x .26 second = 52 mAs). Therefore, choice A is correct.

Apply the 30% Rule to a Film That Was Underexposed