An original radiograph is exposed at 8 mA for 1.0 seconds. If the mA is increased to 10, which of the following exposure times would be correct to maintain radiographic density?

a. 0.4
b. 0.6
c. 0.8
d. 1.0

c. Both milliamperage and exposure time are used to regulate the quantity of x-rays generated, combined into a factor called "milliampere-seconds" (mAs). If one is increased, the other must be decreased in order to maintain radiographic density, according to the formula: mA × s = mAs.