Final answer:
A tiny switch set to on or off is known as a toggle switch, often found in electronic devices powered by button batteries.
Step-by-step explanation:
A tiny switch that can be set to either the on or off position is commonly referred to as a toggle switch. This type of switch is widely used in electronic devices for controlling power or settings. For example, a button battery such as the one described in Figure 5.5.1, may be found in devices like watches, pacemakers, or calculators, where a toggle switch could be used to start or stop the flow of electricity from the battery to the device's components, thereby controlling its functions.