USCG Exam PracticeElectrical basics — generators, motors, and safety
A squirrel-cage induction motor is preferred for most shipboard auxiliary machinery primarily because of which characteristic?
- A. It runs at exactly synchronous speed and can supply leading reactive power
- B. It allows external rotor resistance to be added for high starting torque
- ✓ It is rugged, low cost, and requires no rotor electrical connectionsCorrect
- D. It uses a commutator and carbon brushes to maintain unidirectional current
Why C is correct
DOE-HDBK-1011 Vol.4 §12-1 identifies the squirrel-cage induction motor as dominant in shipboard auxiliaries specifically because of its ruggedness, low cost, and the fact that it needs no rotor connections. Options A and B describe the synchronous motor and wound-rotor induction motor, respectively; option D describes a DC machine.