What distance should the nearest portion of the body be from the tube head and nearest edge of the image receptor when feasible?

• A. 1 meter
• B. 3 meters
• C. 2 meters
• D. 0.5 meters

Answer: (C)

The idea is to minimize the operator’s radiation exposure by increasing distance from the primary beam. Radiation intensity decreases rapidly as distance grows, a principle known as the inverse square relationship. When feasible, keeping your nearest body part away from the tube head and away from the edge of the image receptor—roughly an arm’s length or more—places you outside the high‑intensity area and reduces exposure from both the primary beam and the scatter produced in the patient. This distancing is a practical safeguard that works best when you can position yourself so you are not in the beam’s path, while still performing the radiographic task. If you can’t achieve this distance due to positioning or equipment constraints, rely on protective barriers, shielding, and proper technique to limit exposure.