19 Figure 2E.—Megger circuit. IN ANSWERING QUESTION 2-42, REFER TO FIGURE 2E. 2-42. In the megger circuit, what component prevents leakage current from affecting ohmmeter measurements? 1. Guard ring 2. Generator3. Resistor R3 4. Coil 2-43. When a megger is used to measure an unknown resistance, what circuit action causes the pointer to come to rest at the correct resistance value? 1. The current flow in coil A 2. The current flow in coil B 3. The interaction between the currents in coils A and B 4. The interaction between the restraining springs of the meter and the current in coil A 2-44. A megger uses high voltage to check the insulation leakage in the megohm range. What is the source of this voltage? 1. Batteries 2. The ship's ac power 3. The ship's dc power 4. A hand-driven dc generator2-45. Meggers with which of the following maximum voltage ratings are commonly found in the fleet? 1. 500 volts 2. 700 volts 3. 1,000 volts 4. 2,500 volts 2-46. When a megger is used to measure the resistance of an electrical cable, what does a reading of infinity indicate? 1. The meter is faulty 2. The cable is shorted 3. The cable is grounded 4. The resistance is too large to measure 2-47. A megger is prevented from exceeding its rated output voltage by which of the following actions? 1. Battery discharge limits the voltage 2. Tension in the cable 3. Friction clutch slippage 4. Current leaks through internal insulation 2-48. When the crank of a 500-volt megger is rotated faster than its designed rate, what maximum output voltage does it produce? 1. 100 volts 2. 500 volts 3. 520 volts 4. 550 volts
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