What type of voltage will be applied to the bell when closing switch "x"?

The bell will be energized by a direct current (DC) voltage when switch "x" is closed. In many electrical circuits, especially those involving bells, alarms, and similar devices, DC is commonly used because it provides a steady and consistent flow of electricity. This is essential for devices like bells, as they need a reliable voltage to operate effectively without fluctuations that could affect their performance or reliability.

In contrast, alternating current (AC) may not be suitable for such devices, as it fluctuates in polarity and does not provide the same level of performance. High voltage and low voltage refer to the magnitude of the electrical potential, but the specific application of DC in this context makes it the appropriate answer, as it aligns with how such devices are typically powered in practical applications.