Which of the following best describes the "off" state of voltage in logic gates?

The "off" state in logic gates is typically represented by a low voltage level, which corresponds to the logic level of 0 or false. In digital circuits, when a logic gate is off, it does not allow current to flow, and this is manifested as a low voltage output. This low voltage state is crucial for the operation of digital systems, as it indicates that the gate is not conducting and is effectively not engaged in the logic operation.

The definition of the "off" state being characterized by low voltage is fundamental in understanding binary logic systems, where logic levels are used to represent different states. In contrast, the other choices describe states that would be associated with an "on" condition. For instance, a positive or high voltage would typically indicate the gate is active, while a variable voltage could imply fluctuating states, which does not correspond strictly to the "off" state in the context of binary logic. Thus, understanding the significance of low voltage in the off state is essential for anyone working with logic gates and digital circuits.