Which practice reduces exposure by increasing distance from the source?

Which practice reduces exposure by increasing distance from the source?

• A. Reducing exposure time
• B. Providing shielding
• C. Maintaining a greater distance from the source
• D. Increasing shielding material thickness

Answer: (C)

Distance matters because radiation intensity drops with distance according to the inverse square law: as you move farther from the source, the dose rate decreases rapidly. Doubling the distance cuts exposure to about one-quarter; tripling it reduces exposure to about one-ninth, and so on. This is why maintaining a greater distance from the source directly lowers exposure. Other strategies also help: reducing the time you are exposed lowers the total dose received during a task, and shielding attenuates radiation by absorbing or blocking it. Increasing shielding thickness likewise reduces dose. But the scenario described focuses on how increasing distance alone reduces exposure, which is achieved by staying farther from the source.

Distance matters because radiation intensity drops with distance according to the inverse square law: as you move farther from the source, the dose rate decreases rapidly. Doubling the distance cuts exposure to about one-quarter; tripling it reduces exposure to about one-ninth, and so on. This is why maintaining a greater distance from the source directly lowers exposure.

Other strategies also help: reducing the time you are exposed lowers the total dose received during a task, and shielding attenuates radiation by absorbing or blocking it. Increasing shielding thickness likewise reduces dose. But the scenario described focuses on how increasing distance alone reduces exposure, which is achieved by staying farther from the source.