Clover Learning Rad Tech Boot Camp Practice Test 2026 - Free Rad Tech Practice Questions and Study Guide

To determine the new intensity of x-radiation when the distance to the image receptor changes, you can apply the inverse square law of radiation, which states that the intensity of radiation is inversely proportional to the square of the distance from the source. This principle can be formulated mathematically as:

\[

I_1 / I_2 = (d_2^2) / (d_1^2)

\]

Where:

- \(I_1\) = initial intensity (225 microgray at 25 cm)

- \(I_2\) = new intensity (which we want to find)

- \(d_1\) = initial distance (25 cm)

- \(d_2\) = new distance (75 cm)

First, we calculate the ratio of the distances:

\[

(d_2^2) = (75 \text{ cm})^2 = 5625 \text{ cm}^2

\]

\[

(d_1^2) = (25 \text{ cm})^2 = 625 \text{ cm}^2

\]

Now, substituting these values into the inverse square law gives:

\[

I_1 / I_2 = 562