Question 518Electricity/Electronics - QMED70% to pass
With what device is the RPM of an AC generator indirectly measured on a switchboard when operating singly (no other generator connected to the bus)?
AI Explanation
The correct answer is A) frequency meter.
The RPM of an AC generator is indirectly measured through the frequency of the generated voltage. When a generator is operating singly, without any other generators connected to the bus, the frequency meter on the switchboard will indicate the generator's frequency, which is directly proportional to its RPM. This allows the operator to monitor and adjust the generator's speed to maintain the desired frequency and voltage.
The other options are incorrect because: a voltmeter measures voltage, not RPM or frequency; a synchroscope is used to synchronize generators, not measure individual generator RPM; and synchronizing lamps are used to visually indicate when generators are in sync, not to measure RPM.
Related Questions
#516 Upon failure of the ships normal electrical power supply, by means of what device does the emergency generator supply power to the emergency switchboard, but not the main switchboard? #517 When would be the safest time to close the ship's main switchboard "shore power" circuit breaker? #519 The turns ratio of the step-down transformer with dual voltage secondary as shown in figure "B" of the illustration is two to one (total). If 440 volts were applied to terminals 'H1' and 'H2', what would be measured across 'X1-X3' and 'X2-X4' assuming that the secondary windings are connected in parallel? Illustration EL-0082 #520 In figure "2" of the diagram shown in the illustration, the three phase power transformer has a step-down turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals 'A1-B1-C1’, what voltage should develop across terminals 'A2-B2-C2'? Illustration EL-0084 #521 What is the maximum allowable primary current of a 2 kVA step-down transformer with a four to one turns ratio if the primary is connected across a 440 volt line?