Question 379Electricity & Electronics - Assistant Engineer

The correct answer is B. The buzzer sounding and the masthead indicator light coming on indicates that the primary masthead lamp has failed. To silence the buzzer and illuminate the masthead light, the masthead transfer switch in the line section should be turned to the secondary lamp position. This will switch the circuit to the secondary masthead lamp, silencing the buzzer and illuminating the masthead light. This allows the navigation lights to remain operational while the burned out primary lamp is replaced, minimizing the danger to navigation. The other options are incorrect because: A) Turning the masthead transfer switch off would leave the navigation lights inoperative. C) Turning the master switch off would leave all navigation lights inoperative. D) The buzzer can be silenced, and the masthead light can be illuminated, by switching to the secondary lamp.