CAMRT Radiography Practice Exam

What are the three cardinal rules of radiation protection?

1. Increase speed, use shielding, decrease distance

2. Increase distance, decrease time, use shielding

3. Decrease speed, increase time, use shielding

4. Use shielding, increase speed, decrease dose

The correct answer is: Increase distance, decrease time, use shielding

The three cardinal rules of radiation protection effectively aim to minimize exposure to ionizing radiation. The correct principles are to increase distance, decrease time of exposure, and use shielding. Increasing distance from the source of radiation is vital because the intensity of radiation decreases significantly as one moves further away; this is based on the inverse square law. Reducing the time spent near a radiation source directly decreases the total dose received, as exposure is proportional to time. Lastly, the use of shielding—utilizing materials that can absorb or block radiation—further protects individuals from exposure, depending on the type of radiation involved. The other choices do not align with these established principles of radiation safety. For instance, increasing speed and decreasing distance would actually increase exposure rather than minimize it, while mentioning 'decrease speed' and 'increase dose' contradicts the goal of protection. Thus, the correct combination of increasing distance, decreasing time, and utilizing shielding forms the foundation of radiation safety practices.