Final answer:
Doubling the distance from the x-ray tube to the film reduces patient exposure due to the inverse square law, resulting in a fourfold decrease in radiation intensity at the film. Protective measures, such as shielding and minimizing exposure time, further reduce risks.
Step-by-step explanation:
If the distance from the x-ray tube to the film is doubled, the patient exposure to x-rays would decrease significantly. This is explained by the inverse square law, which states that the intensity of radiation exposure is inversely proportional to the square of the distance from the source of radiation. If the distance is doubled, the area over which the x-rays are spread becomes four times as large, and thus the intensity of the radiation at any given point is reduced to one-fourth of its original value. As a result, the film would be less exposed to radiation, reducing the patient's exposure as well.
To physically limit radiation doses, strategies such as using shielding, increasing the distance from a source, and limiting the time of exposure are employed. In the case of x-ray imaging, using fast films also reduces the time needed to obtain images, subsequently reducing exposure. This practice, alongside other protective measures like using lead aprons and standing behind lead-lined barriers, ensures that the patient and technicians receive the smallest dose necessary to achieve the medical objective.