ABYC Marine Electrical Certification Study Guide with Questions and Answers

ABYC Marine Electrical Certification Study Guide with Questions and Answers A marine technician measures 24 V across a navigation light circuit and finds the circuit current is 4 A. What is the resistance of the load? a. 96 Ω b. 6 Ω c. 20 Ω d. 28 Ω Correct Answer: b. 6 Ω Rationale: Using Ohm’s Law, R = V ÷ I. Therefore, R = 24 ÷ 4 = 6 Ω. Understanding the relationship between voltage, current, and resistance is fundamental to marine electrical troubleshooting. A bilge pump circuit has a resistance of 3 Ω and is supplied with 12 V. What current should be expected under normal operation? a. 4 A b. 9 A c. 36 A d. 0.25 A Correct Answer: a. 4 A Rationale: Ohm’s Law states I = V ÷ R. Therefore, I = 12 ÷ 3 = 4 A. This calculation helps determine whether a circuit is operating within expected limits. A marine electronics device draws 5 A from a 12 V DC system. How much power does the device consume? a. 17 W b. 2.4 W c. 60 W d. 120 W Correct Answer: c. 60 W Rationale: Power is calculated using P = V × I. Therefore, P = 12 × 5 = 60 W. Power calculations are essential when sizing conductors and electrical loads on boats.