Final answer:
The collimator limits the size and shape of the X-ray beam to no more than the area of interest being examined, which is essential for reducing unnecessary exposure to radiation and protecting patient health.
Step-by-step explanation:
The collimator in an X-ray machine is specifically designed to limit the size and shape of the X-ray beam. The function of the collimator is to restrict the X-ray beam to no more than the area of interest being examined. This ensures that only the part of the patient's body which requires imaging is exposed to radiation, reducing unnecessary exposure to other tissues. The use of a collimator, along with other protective measures such as lead aprons and shielding around the X-ray tube, are important safety protocols to minimize exposure and prevent overexposure to X-rays, which can be harmful and increase the risk of conditions such as cancer.