In Diagram II, when is the load energized?

The load is energized when all of the switches are closed because this indicates that the complete circuit is formed and allows current to flow to the load. In a series configuration, each switch must be closed to complete the path for electric current, ensuring that there is no interruption. If even one switch remains open, the circuit remains incomplete, and thus, the load cannot be powered.

This principle emphasizes the importance of each switch in the control scheme, as operating in series directly affects the operation of the load. Other scenarios, such as having any one switch closed or simply turning on the main power, do not guarantee that the load is energized without the necessary state of all switches being closed. The control panel being activated might facilitate the triggering of other components but is not solely responsible for energizing the load without all switches being closed.