A larger ERA beam is associated with which description?

A larger ERA beam is associated with which description?

• A. More collimated beam
• B. More divergent beam
• C. Higher energy density
• D. More column acted beam

Answer: (D)

Increasing the effective radiated area expands the beam’s footprint, so it covers a wider cross-section as it travels through tissue. That means more tissue along the beam’s path is irradiated—the beam acts on a larger column of tissue. That’s why “more column acted beam” best describes a larger ERA beam. The other ideas don’t fit as directly: widening the beam’s cross-section doesn’t inherently make it more collimated, and energy density would typically decrease if the total energy remains the same, not increase.

Increasing the effective radiated area expands the beam’s footprint, so it covers a wider cross-section as it travels through tissue. That means more tissue along the beam’s path is irradiated—the beam acts on a larger column of tissue. That’s why “more column acted beam” best describes a larger ERA beam. The other ideas don’t fit as directly: widening the beam’s cross-section doesn’t inherently make it more collimated, and energy density would typically decrease if the total energy remains the same, not increase.