Question

It is known the intensity of radiation varies inversely to the square of the distance. As one moves away from the source of scatter radiation, they will receive less radiation dose because _

1. the air gap has a tendency to absorb some intensity
2. the scattered photons are much lower in energy
3. the photons are scattered in opposite directions
4. the scattered photons will diverge from the source tissues

Answer 1

Less radiation dose with increased distance from the source is due to the inverse square law, where the intensity of radiation diminishes proportionally with the square of the distance due to scattered photons diverging from the source. The correct answer is option 4.

Step-by-step explanation:

The reason a person receives less radiation dose as they move away from the source of scatter radiation is primarily due to the inverse square law of radiation. This law states that the intensity of radiation varies inversely with the square of the distance from the source.

In other words, if you double your distance from the radiation source, the intensity of the radiation you are exposed to becomes one-fourth of what it was at the closer distance. The correct explanation for the decreased radiation dose with increased distance is the fact that the scattered photons will diverge from the source tissues.

As light or radiation radiates away from its source, it spreads out, causing the energy per unit area to decrease proportionally with the square of the distance. This spreading out of photons is due to their divergence from the source after being scattered, not so much because of absorption by the air (though some slight absorption does occur) or the initial energy of the photons.