AUT 125 ELECTRICAL II CH 54 & 55 CHARGING SYSTEMS

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Clara Hodges
6 years ago
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1 Name: Class: Date: AUT 125 ELECTRICAL II CH 54 & 55 CHARGING SYSTEMS Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Technician A says that the diodes regulate the alternator output voltage. Technician B says that the field current can be computer controlled. Who is right? 2. Where in an alternator is a magnetic field created? a. The frame c. Diodes b. The stator d. The rotor 3. What does the voltage regulator regulate voltage to? a. The alternator field c. The alternator brushes b. The alternator rotor d. All of these 4. Technician A says that two diodes are required for each stator winding lead. Technician B says that diodes change alternating current into direct current. Who is correct? 5. Where is the alternator output produced? a. In the diodes c. Regulator b. In the stator d. Rotor 6. What are alternator brushes made of? a. Copper c. Carbon b. Aluminum d. Silver-copper alloy 7. What is normal field current? a. 10 to 15 amps c. Whatever the alternator puts out b. 2 to 5 amps d. 25 to 35 amps, depending on the vehicle 8. Technician A says that an alternator overrunning pulley is used to reduce vibration and noise, Technician B says that an overrunning alternator pulley or dampener uses a one-way clutch. Who is right? 9. What part of an alternator can be damaged by allowing it to operate in a vehicle with a defective battery? a. The brushes c. The voltage regulator b. The rectification diodes d. The stator 10. Technician A says that a magnetic field is created in the alternator rotor. Technician B says that alternator output is increased if the speed of the alternator is decreased. Who is right? 1

2 Name: 11. Technician A says that current is created in the stator windings of an alternator. Technician B says that the voltage regulator controls the current flow through the rotor. Who is right? 12. How may watts equal one horsepower? a. 500 c b. 746 d. None of these 13. Alternators induce voltage by rotating which of these? a. A conductor around a fixed stator c. Diodes inside a magnetic field b. A stator inside a magnetic field d. A magnetic field inside a fixed conductor 14. The output diodes in an alternator are mounted to which of these components? a. The rotor c. The slip rings b. The housing d. The stator 15. An alternator stator with three windings usually has how many diodes? a. 6 c. 12 b. 18 d What component carries the current from the brushes to the rotor? a. The regulator c. The stator b. The slip rings d. The rotor 17. What is the effect of rising temperature, sensed by the thermistor in the voltage regulator, on voltage regulation? a. It increases voltage c. It has no effect on voltage regulation b. It decreases voltage d. It results in an oscillating voltage 18. Which of these components is the stator? a. A c. C b. B d. D 19. How is the current flow to and from the battery measured on a vehicle using an electrical power management system? a. With a Hall effect sensor c. With an in-line ammeter b. By using a custom voltmeter d. By use of a duty cycle sensor 2

3 Name: 20. What mode of DVOM operation should be chosen to check charging voltage? a. AC volts c. DC amps b. AC amps d. DC volts 21. What mode of DVOM operation should be used to check alternator ripple? a. DC volts c. AC amps b. AC volts d. DC amps 22. Why should the lights be turned on when checking alternator ripple? a. To warm the battery. c. To check that the battery is fully charged. b. To test the battery before conducting other tests. d. To create an electrical load for the alternator 23. What is the generally accepted range of charging voltage in a 12 volt system? a to 15 volts c to 16.1 volts b. 12 to 14 volts d to 15.6 volts 24. Technician A says that the computer can be used to control the output of the alternator by controlling the field current. Technician B says that voltage regulators control the alternator output by controlling the field current through the rotor. Which technician is correct? 25. Technician A says that a voltage drop test of the charging circuit should only be performed when current is flowing through the circuit. Technician B says to connect the leads of a voltmeter to the positive and negative terminals of the battery to measure the voltage drop of the charging system. Who is right? 26. What conclusion can be reached if the resistance between the slip rings and the rotor shaft is observed to be.3 ohms? a. The rotor is shorted to voltage c. The rotor is ok b. The rotor is shorted to ground d. The rotor windings are open 27. What two readings would be obtained from a good diode when checked with a DVOM in the diode check mode. a. OL/OL c. 551 mv/ol b. 300 ohms/300 ohms d. 200 mv/20 MV 28. An alternator could test low in output while still being good if which of the following conditions existed? a. The engine speed was not high enough c. The battery is weak during testing b. The drive belt is slipping d. Any of the above 29. Technician A says that charging system testing requires that the battery be at least 75% charged. Technician B says that a digital multimeter can not be used to test charging system voltage. Who is right? 3

4 Name: 30. Technician A says that by full fielding the alternator, you are bypassing the voltage regulator. Technician B says that full fielding can possibly damage electronic circuits, so it is no longer a recommended test. Who is right? 31. Technician A says when testing for maximum alternator output, the system must be loaded to force the alternator to produce its maximum output. Technician B says after disassembly, all alternator internal components should be tested using an ammeter. Who is right? 32. A vehicle battery is consistently low on voltage. Technician A says to disconnect the battery with the engine running to test for proper alternator output. Technician B says that a loose alternator belt may cause this problem. Who is right? 33. An alternator has zero output. Technician A says that the alternator field circuit may have an open circuit. Technician B says that the fusible link may be open in the alternator to battery wire. Who is right? 34. Technician A says that a loose drive belt could cause overcharging. Technician B says that undersized wiring between the alternator and the battery could cause undercharging. Who is right? 35. What would be wrong with testing alternator ripple in the way illustrated here? (Measuring AC voltage.) a. It would damage the diodes c. It could result in the condemnation of a perfectly good alternator b. Nothing, this is the right way to test for alternator ripple d. This is not the way to test for alternator ripple. It is the way to test volt drop on the alternator s ground circuit 4

5 Name: 36. What test is being performed here? a. Charging current test c. Alternator output voltage drop test b. Alternator ground circuit test d. Battery voltage test 37. Identify this alternator component. a. The stator linkage c. The alternator end housing b. The rectifier bridge d. The diode trio 38. A duty cycle of 90% means the circuit is off most of the time. a. True b. False 39. Some alternators are cooled by engine coolant. a. True b. False 5

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