X-ray equipment operated by single-phase power produces what percentage voltage ripple?

• A. 50%
• B. 75%
• C. 100%
• D. 25%

Answer: (C)

X-ray equipment that operates on single-phase power generates a 100% voltage ripple. This characteristic arises from the nature of single-phase alternating current (AC), where the voltage oscillates between positive and negative peaks. In single-phase systems, the waveform does not provide any smoothing or stabilization that would reduce the fluctuations in voltage during the AC cycle. As a result, the voltage reaches its peak value and drops back to zero, consistently oscillating between these extremes.

When considering ripple percentages, a 100% ripple indicates that the minimum voltage (zero) is essentially half of the maximum voltage level. This high level of fluctuation affects the quality of the X-ray beam produced since there is significant variability in the exposure and overall consistency in imaging.

In contrast, three-phase power, which is more commonly used for higher quality radiographic imaging, has a much lower ripple percentage (typically around 13-25%), which provides a more stable output. This stability allows for improved image quality and reduced radiation dose to patients. Therefore, the nature of single-phase power usage directly correlates with the 100% voltage ripple value.