If the intensity of x-radiation exposing an image receptor is 225 microgray at a distance of 25 cm, what will the intensity be if the image receptor is moved to 75 cm?

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