🔍 Key Concepts

• Look at the reference anodes and protective anodes drawn on the hull and think about what shipboard system uses those terms. • Notice the rectifier bridge and DC output being sent to fittings on the underwater hull rather than to a motor or battery bank. • Compare what you see here with how a battery charger or a depth sounder would normally be connected and what equipment they would show.

💭 Think About

• Ask yourself: which system’s main purpose is to protect the underwater metal structure of the vessel from corrosion? • Why would the circuit need both reference anodes and protective anodes placed around the hull and propeller, and an ammeter in the DC line going to the hull? • Would a synchronous exciter or depth sounding unit be physically connected to the hull in this way, or would they connect mainly to generators/switchboards or to a transducer?

✅ Before You Answer

• Identify which choice is associated with corrosion control of the hull and propeller. • Verify which system normally uses an impressed DC current from a rectifier to underwater anodes on the ship’s structure. • Eliminate any option that would normally connect to batteries or generator fields instead of to hull-mounted anodes.