🔍 Key Concepts

• SCR (Silicon Controlled Rectifier) rectifiers and what they do in a propulsion drive system • Difference between AC generators feeding rectifiers vs DC generators feeding motors • Types of DC propulsion motors commonly used with controlled rectified DC (shunt wound vs series wound)

💭 Think About

• If a system is described as an SCR rectified DC propulsion drive, what form of power must the generator produce so that it can be rectified? • Which type of DC motor (shunt or series) is usually preferred for large ship propulsion when using controlled DC drives, considering speed control and torque characteristics? • Look at each choice and ask: does this setup actually need an SCR rectifier in the first place, or is it already DC or already AC direct to the motor?

✅ Before You Answer

• Verify that an SCR rectifier is used to convert AC to DC, not DC to AC. • Check whether a rectified DC system would logically start with an AC generator or a DC generator. • Confirm which motor type is more typical in modern controlled DC propulsion systems: shunt wound or series wound.