Question 322Electricity/Electronics - QMED70% to pass
In the system shown in the illustration, the engine room station is unable to signal any other station, nor is any other station able to signal the engine room station. The engine room station can, however, ring itself by proper positioning of its selector switch. What is the most probable cause of this problem? Illustration EL-0093
AI Explanation
The correct answer is D) There is an open between terminal "C" of the problem station and the common wire of the multi-conductor cable to the other stations.
This is the correct answer because if there is an open between terminal "C" of the problem station and the common wire, it would prevent any signaling from the other stations from reaching the engine room station. However, the engine room station would still be able to ring itself by positioning the selector switch properly, since that would complete the circuit within the station.
The other answer choices are incorrect because they would either prevent all signaling (A and C) or cause a ground fault (B), which would not match the symptoms described in the question.
Related Questions
#320 As shown in the illustration, assuming power is available at the control circuit, which listed action will occur FIRST when the "off-run" switch is placed in the "run" position? Illustration EL-0017 #321 What type of control circuit logic is featured in the electrical schematic diagram for the motor starting circuit shown in figure "B" of the illustration? Illustration EL-0007 #323 Why are external shunts sometimes used with ammeters? #324 What is the instrument called a galvanometer used to measure? #325 When a resistor is used as a shunt and is connected in parallel with a meter movement coil, what capability does this provide?