Final answer:
Spiral-helical scanners use both high- and low-voltage slip rings for power and data. High-voltage wires on towers are not wrapped in insulating material; air acts as the insulator. Electromagnetic spectrum distinctions are based on frequency and wavelength characteristics.
Step-by-step explanation:
Spiral-helical scanners incorporate c) high- and low-voltage slip rings. This design allows for the transmission of power and data signals necessary for the scanner to function while it rotates around the patient. The high-voltage slip ring is typically used for powering the x-ray tube, while the low-voltage slip rings are used to transfer data and control signals.
Regarding the additional questions: The high-voltage wies that you see connected to tall metal-frame towers are indeed held aloft by insulating connectors, but these wires are typically not wrapped in insulating material because the air around them acts as insulation. Therefore, the statement is b. false.
Lastly, different parts of the electromagnetic spectrum are categorized by their wavelength and frequency. The long-wavelength and low-frequency region corresponds to c. At the low-frequency and long-wavelength end of the spectrum, while the short-wavelength and high-frequency region corresponds to b. At the high-frequency and short-wavelength end of the spectrum.