DANB Radiation Health and Safety (RHS) Practice Exam

The amperage control in an x-ray machine regulates which of the following?

1. Number of free electrons at the cathode filament

2. Speed of electrons toward the target

3. Duration of exposure

4. None of the above

The correct answer is: Number of free electrons at the cathode filament

The amperage control in an x-ray machine primarily regulates the number of free electrons at the cathode filament. Amperage, or current, directly correlates to the quantity of electrons that are produced when the cathode is heated. When the filament current is increased, more electrons are released, leading to a higher potential for x-ray production during the exposure phase. This control is crucial because it influences the intensity of the x-ray beam, which in turn affects the overall density of the radiographic image. A higher amperage results in more x-rays being generated, potentially leading to a darker image on the film. Understanding how amperage impacts the generation of x-rays helps in fine-tuning the machine for various imaging needs while considering patient safety and image quality.