Calculate the milliroentgens per milliampere-seconds if 400 mA and 12 ms yield an output exposure of 150 mR.

Calculate the milliroentgens per milliampere-seconds if 400 mA and 12 ms yield an output exposure of 150 mR.

• A. 0.32
• B. 3.1
• C. 17.6
• D. 31

Answer: (D)

To determine the milliroentgens per milliampere-seconds, you start with the given exposure and the product of the current and the time. In this situation, the exposure is 150 mR, the current is 400 mA, and the time is 12 ms. First, convert the time from milliseconds to seconds for consistency in the calculation. Since 12 ms is equal to 0.012 seconds, you can proceed with the calculation. Next, calculate the milliampere-seconds: \[ mA \cdot s = 400 \, mA \times 0.012 \, s = 4.8 \, mAs \] Now, you can calculate the output exposure in milliroentgens per milliampere-second (mR/mAs): To find mR per mAs, divide the exposure (150 mR) by the milliampere-seconds (4.8 mAs): \[ \frac{150 \, mR}{4.8 \, mAs} = 31.25 \, \frac{mR}{mAs} \] Rounding this to two decimal places gives approximately 31 mR/mAs. This indicates that

To determine the milliroentgens per milliampere-seconds, you start with the given exposure and the product of the current and the time. In this situation, the exposure is 150 mR, the current is 400 mA, and the time is 12 ms.

First, convert the time from milliseconds to seconds for consistency in the calculation. Since 12 ms is equal to 0.012 seconds, you can proceed with the calculation.

Next, calculate the milliampere-seconds:

[

mA \cdot s = 400 , mA \times 0.012 , s = 4.8 , mAs

]

Now, you can calculate the output exposure in milliroentgens per milliampere-second (mR/mAs):

To find mR per mAs, divide the exposure (150 mR) by the milliampere-seconds (4.8 mAs):

[

\frac{150 , mR}{4.8 , mAs} = 31.25 , \frac{mR}{mAs}

]

Rounding this to two decimal places gives approximately 31 mR/mAs.

This indicates that