Question

which of the following exposure settings will produce a radiograph with the least amount of motion blur?
○ 260 milliamperes (ma) and 0.0025 seconds (s)
○ 380 milliamperes (ma) and 0.00125 seconds (s)
○ 420 milliamperes (ma) and 0.001 seconds (s)
○ 660 milliamperes (ma) and 0.01 seconds (s)

Explanation:

To determine which setting produces the least motion blur, we calculate the product of mA and time (mAs) for each option, as a shorter exposure time (lower mAs) reduces motion blur.

Step1: Calculate mAs for first option

mA = 260, time = 0.0025 s
mAs = \( 260 \times 0.0025 = 0.65 \)

Step2: Calculate mAs for second option

mA = 380, time = 0.00125 s
mAs = \( 380 \times 0.00125 = 0.475 \)

Step3: Calculate mAs for third option

mA = 420, time = 0.001 s
mAs = \( 420 \times 0.001 = 0.42 \)

Step4: Calculate mAs for fourth option

mA = 660, time = 0.01 s
mAs = \( 660 \times 0.01 = 6.6 \)

The smallest mAs value (0.42) corresponds to 420 mA and 0.001 s, which means the shortest exposure time, minimizing motion blur.

Answer:

420 milliamperes (mA) and 0.001 seconds (s)