25 August 2016

ELECTRICAL QUESTIONS AND ANSWERS-MCQ-8-ETO


QUESTIONS AND ANSWERS FOR ETO

1. The state of charge of a lead acid storage battery is best indicated by the _____________.
A. testing of the individual cell voltages      
B. ampere hour capacity of the battery      
C. specific gravity of the electrolyte             
D. total cell voltages        
Ans: C

2. Which of the following statements is correct concerning the circuits in a sound powered telephone system? 
A. The ringing circuit is composed of only one common wire to ground.           
B. The common talking circuit is composed of two ungrounded wires.              
C. The ringing circuit has two grounded wires connected to each station.       
D. The talking and calling circuits are electrically dependent upon each other.              
Ans: B

3. The first requirement for logical troubleshooting of any system is the ability to ______________.     
A. collect all available data on a casualty   
B. recognize normal operation      
C. identify the probable cause of a symptom            
D. isolate the faulty component    
Ans: B

4. The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ____________.  
A. load limit settings        
B. idle speed settings       
C. speed limit settings     
D. speed droop settings  
Ans: D

5. What type of rotor is used in split-phase motors?              
A. Drum               
B. Salient pole    
C. Squirrel-cage 
D. Wound-rotor 
Ans: C

6. Tightly knit metal braid wire can be used with a printed circuit board when ___________.
A. conductor flexibility is required
B. desoldering components in the circuit   
C. electrically produced magnetic fluxes would cause inaccuracies in adjacent components      
D. reactance in the circuit must be kept to a minimum          
Ans: B

7. The open-circuit voltage of a fully charged lead-acid  battery cell is _____________.              
A. 1.5 volts          
B. 1.8 volts          
C. 2.0 volts          
D. 2.3 volts          
Ans: C

8. AC circuits possess characteristics of resistance,   inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________.           
A. ohms
B. mhos
C. henrys             
D. farads              
Ans: A

9. A low voltage source is being used for testing armature  coils. A coil short circuit will be indicated by a _______.         
A. high voltage reading, while the other coil readings will have an equal or lower value              
B. low or zero voltage reading, while the other coils will have higher readings               
C. fluctuating voltmeter reading, while the other coil readings are steady      
D. steady voltmeter reading, while the other coil readings are fluctuating      
Ans: B

10. In an AC generator, direct current from a separate source is passed through the windings of the rotor _____________.        
A. by means of slip rings and brushes          
B. by means of a commutator       
C. by means of rotating bar magnet            
D. to minimize the danger of arc over         
Ans: A

11. The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________.
A. provide excitation to the DC field            
B. start the machine as an induction motor
C. contribute extra torque at synchronous speed    
D. prevent the machine from falling out of step       
Ans: B

12. Motor controllers are seldom troubled with grounds because _____________.     
A. the auxiliary contacts have a high resistance connection 
B. the contactors and relays are mounted on a non-conducting panel              
C. the resistor banks are composed of individual series-connected units         
D. there are separate switches for the motor and the control            
Ans: B

13. A delayed-action fuse is most frequently used in which of the listed circuits?          
A. Lighting circuit              
B. Motor circuit 
C. Electric heater circuit  
D. Radar circuit  
Ans: B

14. The electrical energy necessary to transmit a person's voice over a sound-powered telephone circuit is obtained from  _____________.               
A. dry cell batteries          
B. the ship's service switchboard 
C. the emergency switchboard     
D. the speaker's voice      
Ans: D

15. Which of the listed procedures should be carried out to  prevent moisture damage to electrical apparatus during  extended periods of idleness?
A. Fill the motor housing with CO2 to inert the space.           
B. Strap silica gel around the commutator.               
C. Place heat lamps in the motor housings.
D. Cover the equipment with a canvas tarpaulin.    
Ans: C

16. A constant output voltage from an AC generator is maintained by the _____________.     
A. prime mover governor
B. exciter generator         
C. voltage regulator         
D. reverse power relay    
Ans: C

17. Amortisseur windings are installed in a synchronous motor to _____________.    
A. reduce eddy current losses       
B. produce a higher power factor 
C. provide a means for starting     
D. eliminate arcing between the stator and the rotor            
Ans: C

18. Electric strip heaters are used in motor controllers to  _____________.  
A. prevent freezing of movable contacts    
B. keep the components at their design ambient temperature           
C. prevent condensation of moisture          
D. minimize resistance in internal circuits 
Ans: C

19. A fuse that blows often should be replaced only with a fuse of _____________.    
A. the recommended current and voltage rating     
B. higher current and voltage rating            
C. higher current and lower voltage rating
D. lower current and higher voltage rating
Ans: A

20. Which of the listed conditions is an advantage of a PN diode over a vacuum diode?              
A. Longer life.     
B. No warm up time.        
C. Less delicate.
D. All of the above.           
Ans: D

21. The freezing point of the electrolyte in a fully charged lead-acid battery will be _____________.     
A. higher than in a discharged battery        
B. lower than in a discharged battery         
C. the same as in a discharged battery       
D. higher than in a discharged battery, but the specific  gravity will be less    
Ans: B

22. The heating of conductors as a result of resistance in a distribution circuit causes a power loss expressed as  _____________.               
A. line droop       
B. line loss           
C. IR drop            
D. hysteresis      
Ans: B

23. To repair a small electrical motor that has been submerged in saltwater, you should _____________.
A. wash it with fresh water and apply an external source of heat       
B. renew the windings     
C. send it ashore to an approved service facility      
D. rinse all electrical parts with a carbon tetrachloride  cleaning solvent and then blow dry the motor with compressed air           
Ans: A

24. The output voltage of a three-phase alternator is regulated by the _____________.           
A. AC voltage to the armature      
B. AC voltage to the field
C. DC voltage to the armature      
D. DC voltage to the field
Ans: D

25. The function of damper windings in a synchronous motor is to _____________.    
A. eliminate slippage        
B. provide excitation        
C. provide starting torque              
D. increase efficiency       

Ans: C


"Trust because you are willing to accept the risk, not because it's safe or certain." --Anonymous

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ELECTRICAL QUESTIONS AND ANSWERS-MCQ-8-ETO
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