ASNT Industrial Radiography Radiation Safety Practice Test

What is the effect of increasing distance on radiation exposure?

1. It increases exposure significantly

2. It decreases exposure due to the inverse square law

3. It has no effect on exposure

4. It doubles the exposure

The correct answer is: It decreases exposure due to the inverse square law

Increasing distance has a significant effect on radiation exposure, primarily due to the inverse square law. This law states that the intensity of radiation is inversely proportional to the square of the distance from the source of radiation. As you move farther away from the radiation source, the exposure decreases dramatically. For example, if you double the distance from the radiation source, the exposure will reduce to a quarter of what it was at the original distance. This principle highlights the importance of maintaining adequate distances when working in environments where radiation is present, as it is one of the most effective ways to minimize exposure and enhance safety. Understanding this relationship is crucial in radiation safety practices for protecting both workers and the public from unnecessary radiation exposure.