🔍 Key Concepts

• AC generator (alternator) fundamentals – relationship between field strength, speed, and output voltage • For a 60 Hz ship’s service generator, which parameter is kept essentially constant during normal operation? • Role of the exciter and field current in controlling alternator voltage

💭 Think About

• If the frequency must remain at 60 Hz, what does that tell you about how much you can change the prime mover speed to control voltage? • Does changing the electrical load directly control the generator’s voltage, or does the generator’s voltage regulator act to keep voltage constant as load changes? • Which component actually changes the strength of the magnetic field in the alternator to adjust output voltage?

✅ Before You Answer

• Identify which option directly affects the generator field current or magnetic field strength. • Confirm which options would undesirably change frequency (Hz) if you used them to control voltage. • Eliminate any choices that only change mechanical load or torque but do not directly adjust the generator’s excitation or field.