Which component may be responsible for mismatches in the kVp output during quality-control testing?

The auto transformer plays a crucial role in adjusting the voltage supplied to the primary side of the step-up transformer, which ultimately influences the kVp output. During quality-control testing, any irregularities or malfunctions within the auto transformer can lead to inconsistencies in the voltage levels it outputs. If the auto transformer is not functioning correctly, it may not provide the necessary voltage to achieve the desired kilovolt peak (kVp), causing discrepancies in the output.

In contrast, the step-up transformer is designed to increase the voltage but relies on the input from the auto transformer to function correctly; therefore, any variability from the auto transformer directly affects the kVp. The circuit breaker primarily serves as a safety device to protect the circuit from overload, while the exposure timer controls the duration of exposure but does not directly affect the voltage output. Thus, the auto transformer is fundamental in ensuring consistent and accurate voltage levels, making it responsible for potential mismatches in the kVp output during quality tests.