Question

which modifications may decrease the total exposure time when using an automatic exposure control (aec) system?
increased milliamperage (ma)
decreased kilovoltage peak (kvp)
decreased back - up timer
increased density setting

Explanation:

In an automatic exposure control (AEC) system, the product of milliamperage (mA) and exposure time (mAs) is related to the amount of radiation reaching the detector. Increasing the mA allows for a shorter exposure time to achieve the same level of exposure. Decreasing kVp would increase exposure time to maintain image quality. Decreasing backup timer just sets a limit and doesn't directly decrease normal exposure time. Increasing density setting doesn't decrease exposure time.

Answer:

Increased milliamperage (mA)