Without line voltage compensation, what is the likely effect on radiographic exposure?

• A. Voltage fluctuations have no impact on exposure when compensation is not used.
• B. Exposure will be inconsistent due to kVp variations without compensation.
• C. Filtration is automatically altered by the voltage.
• D. The timer lengthens exposure to compensate.

Answer: (B)

Line voltage compensation keeps the actual tube voltage steady despite fluctuations in the power supply. Without it, changes in the incoming voltage cause the kilovolt peak (kVp) delivered to the x-ray tube to vary. Since kVp largely determines beam penetrability and the resulting image density and contrast, these variations produce inconsistent radiographic exposure even if mA and exposure time stay the same. Filtration isn’t automatically altered by voltage, and the timer isn’t designed to compensate for voltage swings—that’s a separate concern. So the exposure becomes unreliable because kVp varies when there’s no line voltage compensation.