Final answer:
The factors that directly affect patient exposure to radiation except 3 phase generator (Option 2).
Step-by-step explanation:
The factors that directly affect patient exposure in radiographic imaging are:
- Exposure time: Less time means less exposure to radiation.
- Target-to-panel distance: Radiation intensity drops inversely proportional to the square of the distance from the radiation source.
- Collimation: This allows a portion of the rays to be selectively aimed at the target area, reducing exposure to surrounding tissues.
A 3-phase generator, while it can affect the quality of the X-ray image, does not directly affect the radiation dose the patient receives. Instead, it alters the voltage waveform supplied to the X-ray tube, influencing factors like beam quality and exposure time efficiency.
Thus, the correct option is number 2.