MTC Marine Technician Electrical & Electronics 2

Question 1

What is the purpose of a marine alternator's voltage regulator?

Accepted Answer

To maintain a constant output voltage regardless of engine RPM

Answer

The voltage regulator keeps alternator output at a stable voltage (typically 13.8–14.4V) across varying engine speeds.

Question 2

A marine VHF radio suddenly displays 'LOW VOLTAGE' during operation. The most likely cause is:

Accepted Answer

Insufficient battery charge or poor wiring connections

Answer

Low voltage warnings on marine electronics typically indicate battery depletion or high-resistance connections in the supply circuit.

Question 3

Which wire color is standardized for DC negative (ground) in ABYC marine wiring?

Accepted Answer

Black or yellow

Answer

ABYC standards designate black or yellow as the color for DC negative conductors in marine electrical systems.

Question 4

What does a marine GFCI (Ground Fault Circuit Interrupter) protect against?

Accepted Answer

Electric shock by detecting small current leakage to ground

Answer

A GFCI monitors the difference in current between hot and neutral conductors, tripping when leakage current (as low as 4–6 mA) flows to ground.

Question 5

On a marine depth sounder, the transducer sends and receives which type of energy?

Accepted Answer

Ultrasonic sound waves

Answer

Depth sounders use ultrasonic (high-frequency sound) pulses that travel through water and reflect off the bottom to calculate depth.

(MTC) Marine Technician Certification Practice Test