What mA is required to achieve 15 mAs if an exposure time of 0.05 seconds is selected?

To determine the necessary milliamperes (mA) to achieve a specific milliampere-seconds (mAs) when given the exposure time, you can use the following formula:

mAs = mA × exposure time (in seconds)

In this case, you want to find mA when the mAs is 15 and the exposure time is 0.05 seconds. Rearranging the formula to solve for mA gives:

mA = mAs / exposure time

Substituting the values you have:

mA = 15 mAs / 0.05 seconds

Calculating that gives:

mA = 15 / 0.05 = 300

Thus, to achieve 15 mAs with an exposure time of 0.05 seconds, 300 mA is required. This calculation confirms that the correct answer is indeed associated with a setting of 300 mA, making it essential to understand how the relationship between mA, exposure time, and mAs works in imaging practices.