🔍 Key Concepts

• Look at the labels at each station such as "Rings on #4/#6/#7/#9" and think about what type of system "rings" different locations. • Notice the multiple lines running to many stations and the selector dial numbered 1–11 at each station – consider what kind of equipment lets you choose which station to contact. • Compare the diagram to how an engine order telegraph, a rudder angle indicator, and a tachometer are normally arranged (do they have many parallel communication lines, or just signal/feedback pairs?).

💭 Think About

• Ask yourself: which of the four choices must be able to call several different locations and make them "ring" before using it? • Would a rudder angle indicator or tachometer need a station selector switch with many wires going to other spaces, or only a transmit/receive pair between bridge and machinery space? • Which system in the answer choices is primarily a communication circuit rather than a measuring/indicating instrument?

✅ Before You Answer

• Verify which answer choices are measuring devices (indicators of speed or rudder angle) versus communication systems. • Check whether an engine order telegraph normally has a numbered station selector like 1–11, or specific command positions like STOP, AHEAD, ASTERN, etc. • Confirm that the presence of multiple pairs of wires and a "rings on #" label indicates a system designed to signal or talk between many stations, not simply show a single value.