Marine Electrical MCQ Part-1

 

Marine Electrical MCQ

1. Moisture damage, as a result of condensation occurring inside the cargo winch master switches, can be reduced by __________________.

a. installing a light bulb in the pedestal stand

b. coating the switch box internals with epoxy sealer

c. venting the switch box regularly

d. using strip heaters inside the switch box

2. Low horsepower, polyphase, induction motors can be started with full voltage by means of ___________.

a. compensator starters

b. autotransformer starters

c. across-the-line starters

d. primary-resistor starters

3.  An operating characteristic appearing on the name plates of shipboard AC motors is _____________.

a. the type of winding

b. input kilowatts

c. temperature rise

d. locked rotor torque

4.  Brushless generators are designed to operate without the use of ___________.

a. brushes

b. slip rings

c. commutators

d. all of the above

5.   The shunt used in an ammeter should be connected in____________.

a. series with the load and in parallel with the meter movement

b. parallel with the load and in series with the meter movement

c. parallel with the load and in parallel with the meter movement

d. series with the load and in series with the meter movement

6.  A semiconductor that decreases in resistance with an increase in temperature is known as a ___________.

a. resistor

b. thermistor

c. diode

d. thermopile

7.  A three-phase alternator is operating at 450 volts with the switchboard ammeter indicating 300 amps. The kw meter currently indicates 163.6 KW, with a power factor of 0.7. If the power factor increases to 0.8, the KW meter reading would increase by ____________.

a. 17.8 KW

b.  23.4 KW

c. 30.6 KW

d. 37.8 KW

8.  An electric tachometer receives the engine speed signal from a _______________.

a. small generator mounted on the engine

b. bimetallic sensing device

c. stroboscopic sensing device

d. vibrating reed meter generating a voltage proportionate to engine speed

9. When troubleshooting most electronic circuits, "loading effect" can be minimized by using a voltmeter  with a/an ___________________.

a. input impedance much greater than the impedance across which the voltage is being measured

b. input impedance much less than the impedance across which the voltage is being measured

c. sensitivity of less than 1000 ohms/volt

d. sensitivity of more than 1000 volts/ohm

10. The full torque electric brake on an electric cargo winch functions to _____________.

a. act as a backup brake in the event the mechanical brake should fail

b. automatically hold the load as soon as current to the machine is shut off

c. automatically govern the lowering speed of the load

d. automatically govern the hoisting speed of the load

11. Time delayed or delayed action-type fuses are designed to _____________.

a. prevent grounds in branch circuits

b. prevent opens in motor circuits

c. permit momentary overloads without melting

d. guard lighting and electronic circuits 

12. For a given line voltage, four heating coils will produce maximum heat when connected in

a. parallel 

b. series

c. same heat in both the time

d. none of the above

13. The main use of a Class-C amplifier is__________.

a. as an RF amplifier

b. as stereo amplifier

c. in communication sound equipment

d. as distortion generator 

14. Large cable sizes are formed as individual conductors that may be comprised of several smaller strands to________.

a. obtain the flexibility required for easy handling   

b. reduce the overall weight of the wire run

c. reduce the number of supports needed for a horizontal overhead run

d. all of the above

15. Which of the following statements represents an application of a silicon controlled rectifier?

a. To provide DC power for a main propulsion motor

b. For use as a voltage reference diode.

c. For sensing flame in an automated burner. 

d. To eliminate power supply.

16. Reversing any two of the three rotor leads on induction motor will ________.

a. increase motor performance

b. decrease motor performance

c. reverse the motor

d. have no effect on the direction of rotation or motor performance

17. Which of the following does not change in a transformer______.

a. Current

b. Voltage

c. Frequency 

18. The depletion region in semiconductor diode is due to________.

a. Reverse biasing          

b. forward biasing

c. crystal doping

d. migration of mobile charge carriers 

19. Common emitter amplifier is characterized by________.

a. Low voltage gain

b. Moderate power gain

c. signal phase reversal

d. very high output impedance

20. Max full wave rectifier efficiency possible by two diodes from a sinusoidal wave is________.

a. 80.2

b. 82.1

c. 81.2

d. None of the above

Marine Electrical MCQ Part-2