Questions and Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a marine battery switch?
A. Increase voltage
B. Disconnect batteries from loads
C. Charge batteries faster
D. Reduce resistance
Answer: B
Rationale: A battery switch isolates electrical systems for safety and
maintenance.
2. According to ABYC standards, what color is typically used for DC
negative conductors?
A. Red
B. Yellow or black
C. Green
,D. Blue
Answer: B
Rationale: ABYC specifies yellow (preferred) or black for DC negative
conductors.
3. What device protects a circuit from overcurrent?
A. Relay
B. Switch
C. Fuse or circuit breaker
D. Transformer
Answer: C
Rationale: Fuses and breakers interrupt current flow when it exceeds
safe levels.
4. What is the minimum requirement for overcurrent protection
location?
A. At the load
B. At the battery or source
C. Midway in circuit
D. Anywhere convenient
,Answer: B
Rationale: Protection must be as close as possible to the power source.
5. What does AWG stand for?
A. American Wire Gauge
B. Alternating Wire Grid
C. Ampere Watt Guide
D. Automatic Wire Grade
Answer: A
Rationale: AWG is the standard for wire sizing in North America.
6. What is the main function of a galvanic isolator?
A. Increase voltage
B. Prevent galvanic corrosion
C. Improve signal strength
D. Store energy
Answer: B
Rationale: It blocks low-voltage DC currents that cause corrosion.
, 7. What type of current is used in most onboard DC systems?
A. Alternating current
B. Direct current
C. Pulsating current
D. Static current
Answer: B
Rationale: Marine batteries supply direct current.
8. What is the standard nominal voltage of a typical marine battery?
A. 6V
B. 12V
C. 24V
D. 48V
Answer: B
Rationale: Most marine systems operate on 12V DC.
9. What does a circuit breaker do when tripped?
A. Increases voltage
B. Opens the circuit
C. Stores energy
D. Grounds the circuit