The extension of the vertical control busses can be visualized as the ___________ ___________ of a ladder.
This makes the same control power available to additional control lines, which can be added in parallel as successive __________ on the same ladder.
Each ___________ or additional control line operates in parallel with all the other control lines of the common AC source.
A) rungs; rung; side rails;
B) side rails; side rails; rung
C) rungs; rung; rungs
D) side rails; rungs; rung
Show Answer
Answer:D
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