Question 185Electricity & Electronics - Assistant Engineer

70% to pass

How is the main propeller shaft rotation of a rectified DC diesel-electric drive normally reversed?

Areversing the field polarity in the DC motor
Breversing the diesel engine rotation
Creversing the field polarity in the AC generator
Dreversing the interpoles
AI Explanation

The correct answer is A) reversing the field polarity in the DC motor. In a rectified DC diesel-electric drive, the main propeller shaft rotation is reversed by changing the polarity of the field windings in the DC motor. This allows the motor to run in the opposite direction, which then reverses the rotation of the propeller shaft. The other options are incorrect because they do not directly address the mechanism for reversing the DC motor, which is the key component in a diesel-electric drive system.

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Official Resources
46 CFR Electrical Engineering 46 CFR Machinery & Electrical USCG National Maritime Center
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